| Takeaway | Detail |
|---|---|
| Sticker pricing masks true pilot economics due to input-output asymmetry and caching. | Blended costs compress the apparent gap to under 2x when accounting for typical 3:1 prompt-to-response ratios and cached-input discounts. |
| Batch API utilization fundamentally alters unit economics for enterprise workloads. | OpenAI's 50% Batch API discount applied to standard rates yields a blended cost of $0.0044 per 1K tokens, drastically narrowing the spread against open-weight alternatives. |
| Self-hosting becomes economically dominant at scale despite higher infrastructure overhead. | Beyond approximately 2 billion tokens monthly, running Llama 3.1 70B on-premises inverts the cost curve entirely compared to cloud inference. |
| Governance councils must standardize which pricing metric drives procurement decisions. | The choice between raw sticker rates and blended operational figures directly impacts whether a deployment meets the sub-$0.001 per-request viability threshold required for high-volume agentic tasks. |
At a standard three-to-one input-to-output ratio, GPT-4o registers a blended rate of $0.0044 per one thousand tokens, while Llama 3.1 70B on Together AI sits at $0.00088. That headline fivefold disparity immediately captures executive attention, yet it represents a static snapshot rather than an operational reality. When governance teams factor in OpenAI’s fifty percent batch processing reduction alongside cached-input pricing tiers, the effective spread collapses to just eighteen hundredths of a point. Pilot budgets therefore hinge less on raw model selection and more on which accounting methodology the finance committee actually approves.
This mathematical compression reveals that the perceived premium for frontier closed models is largely an artifact of how token consumption gets tallied across asymmetric conversation flows. Real-world deployments rarely process uniform batches; they generate lengthy reasoning traces, parse documents, and route follow-up queries through identical context windows. Caching eliminates redundant computation, while asynchronous batch queues absorb latency spikes without triggering premium throughput fees. The resulting blended figure consistently tracks closer to parity with mid-tier open weights once these mechanical adjustments are applied.
Enterprise procurement frameworks must therefore shift from comparing list prices to modeling actual workload topology. Organizations pushing beyond two billion tokens monthly will find self-hosted architectures invert the traditional cost hierarchy, especially when factoring in the broader market pressure that demands sub-$0.001 per-request thresholds for scalable automation. Aligning technical architecture with approved financial metrics prevents budget overruns and ensures that agentic initiatives deliver the documented one hundred seventy-one percent return observed across mature deployments.

The Pricing Stack
The pilot budget must account for the blended cost formula: blended = (input_ratio × input_price) + (output_ratio × output_price). At a standard 3:1 input-output ratio, GPT-4o computes to $0.0044 per 1K tokens. Llama 3.1 70B, priced at roughly $0.00088 per 1K on hosted endpoints, yields a blended figure near $0.00088 assuming similar tokenization efficiency. The raw gap sits at approximately 5x, but this ignores OpenAI's two structural levers that compress effective pricing: the Batch API reduces costs by 50% (dropping to $1.25/$5.00 per 1M), and prompt caching applies a 50% discount on cached input tokens ($1.25 per 1M). Hosted Llama providers generally price flat without caching tiers, meaning batched GPT-4o workloads can approach Llama's served cost floor.
For sustained volume, self-hosting introduces a throughput-based cost floor. Serving FP8 Llama 3.1 70B requires roughly 2× 80GB GPUs, such as a pair of H100s. On 2026 spot markets running ~$2.50–$3.50 per H100-hour, a dedicated pair at 60% utilization establishes a floor near $0.0002–$0.0004 per 1K tokens. This threshold renders self-hosting competitive only above sustained monthly volumes, typically exceeding 2B tokens, where amortization erodes the hosted endpoint premium.
A hidden distortion skews all per-token comparisons: tokenizer variance. GPT-4o uses the o200k_base vocabulary, while Llama 3.1 relies on a 128K-vocabulary tokenizer. Identical source documents tokenize 5–15% differently across models, inflating apparent token counts for one model relative to the other. Budgeting must normalize on identical tokenized inputs rather than raw text length to avoid mispricing the true cost delta.
OpenAI’s published pricing page for the 2026 pilot window establishes a rigid metering baseline: $2.50 per 1M input tokens, $10.00 per 1M output tokens, and $1.25 per 1M cached input tokens, with Batch API halving each figure. According to OpenAI's pricing documentation, these rates lock in a steep output premium that distorts budget planning when applied to synchronous, uncached workloads. The sticker ratio implies a fivefold gap over open-weight alternatives, but that arithmetic collapses the moment you account for how enterprise traffic actually flows through production pipelines.
| Metering Lever | GPT-4o Effective Cost | Llama 3.1 70B Effective Cost | Budget Impact |
|---|---|---|---|
| List Price (3:1 Ratio) | $0.0044 / 1K | $0.00088 / 1K | Sticker gap ≈ 5x; misleading baseline |
| Batch API / Caching | Drops via 50% off-list rates | No caching tier; flat rate | Cached batch GPT-4o narrows gap significantly |
| Self-Host Floor (FP8) | N/A | $0.0002–$0.0004 / 1K @ 60% util | Self-host wins only >2B tokens/month |
| Tokenizer Variance | o200k_base | 128K vocabulary | Normalize inputs; raw text comparison invalid |

The 2026 Price Sheet
Llama 3.1 70B served rates across three major endpoints cluster tightly together. According to Together AI's public model catalog page, the flat rate sits at $0.88 per 1M tokens. Fireworks AI's catalog lists $0.90 per 1M, while AWS Bedrock's model index charges $0.99 per 1M for both input and output. The spread between these providers measures under 13%, which means vendor selection should be driven by SLA guarantees and region-specific latency rather than raw token pricing. Model choice dominates provider choice in this tier.
Quality-to-cost alignment is where the real budget decision lives. According to Artificial Analysis's published model comparison tables, Llama 3.1 70B served via Together AI scores within roughly 10–15% of GPT-4o on aggregated reasoning and coding evals (MMLU, HumanEval, MT-Bench-style composites) while priced at roughly one-fifth the blended rate. That performance delta is narrow enough that most enterprise pilots can absorb it without triggering rework costs, provided the task does not require deep multi-step chain-of-thought or highly specialized domain reasoning.
Vendor-side positioning reinforces this compression. According to Meta's own Llama 3.1 launch materials, Meta's published cost comparison pegged Llama 3.1 405B on hosted endpoints at roughly half the cost of GPT-4o, and 70B at roughly a quarter. Those claims align with the independent provider quotes above and confirm that the open-weight stack has moved from academic curiosity to production-grade economics. The gap is no longer theoretical; it is baked into the contract terms.
The crossover point shifts dramatically once you move off-hosted endpoints. At approximately $3.00 per H100-hour and measured Together AI-style throughput (~2,500 output tokens/sec per GPU-pair under vLLM FP8 serving), dedicated infrastructure beats the $0.88/1M hosted rate once monthly volume sustains above roughly 1.5–2B tokens. This threshold is a derived estimate from published GPU spot rates and vLLM benchmark throughput, not a vendor quote, but it maps directly to how procurement teams amortize capital expenditure against variable cloud spend. Above that volume, the hosted endpoint becomes a convenience tax rather than a cost optimization.
The myth that Llama 3.1 70B is always five times cheaper than GPT-4o only survives in isolated, uncached, output-heavy call patterns. Once you layer prompt caching, batch scheduling, and self-hosting amortization into the ledger, the effective ratio compresses to under two times for most enterprise traffic profiles. Budget against the blended operational curve, not the headline price sheet.
| Provider / Source | Rate Structure | Key Constraint | When It Wins |
|---|---|---|---|
| OpenAI (GPT-4o) | $2.50/$10.00 per 1M tokens; $1.25 cached; 50% batch discount | Output-heavy sync calls inflate blended cost | Tasks requiring >5-point quality delta on internal evals |
| Together AI (Llama 3.1 70B) | $0.88 per 1M tokens flat | No native prompt caching discount listed | Baseline pilot routing; highest throughput stability |
| Fireworks AI (Llama 3.1 70B) | $0.90 per 1M tokens | Slightly higher base rate | Regions where Together lacks low-latency edge nodes |
| AWS Bedrock (Llama 3.1 70B) | $0.99 per 1M tokens (input/output) | Uniform pricing removes input/output asymmetry | Organizations already locked into AWS compliance frameworks |
| Artificial Analysis (Benchmark) | 10–15% performance delta vs GPT-4o on MMLU/HumanEval/MT-Bench | Aggregated metrics mask edge-case failures | Standard reasoning/coding tasks where rework risk is low |
| Self-Hosted (vLLM FP8) | Crossover at ~1.5–2B tokens/month at $3.00/H100-hour | Requires upfront GPU procurement and ops overhead | High-volume, predictable workloads exceeding 2B tokens monthly |
At a standard 3:1 input-output ratio, the arithmetic exposes a structural asymmetry in how models price context versus generation. GPT-4o's blended cost calculates to $0.004375 per 1K tokens via the formula (0.75 × $0.0025) + (0.25 × $0.0100), while Llama 3.1 70B on Together AI sits at a flat $0.00088 per 1K. This yields a raw sticker ratio of 4.97x, a figure that misleads budgeting because it ignores how workload topology and caching compress that delta. When you apply batch pricing tiers and prompt caching, the effective GPT-4o ratio collapses to roughly 2.5x, proving the headline gap is a function of call pattern, not model capability.

Blended Cost per 1K
Raw cost alone fails to capture value density. Using Artificial Analysis's composite score as the quality proxy, we compute cost-per-quality-point by dividing the blended price by the composite score. Llama 3.1 70B wins on cost-per-quality across all four archetypes, but the margins range from 1.6x to 4.4x rather than the naive 5x. This compression occurs because GPT-4o's higher baseline quality offsets its token premium in output-heavy scenarios, yet it never fully bridges the efficiency gap. The table's explicit overall winner for 2026 pilots remains Llama 3.1 70B on a hosted endpoint like Together AI or Fireworks, which secures raw and quality-adjusted cost leadership in three of four workloads. GPT-4o claims only the cached-conversational archetype, and even there, victory requires cache hit rates exceeding 70% to leverage the $1.25/1M cached input rate effectively.
| Workload Archetype | Ratio / Condition | GPT-4o Blended Cost | Llama 3.1 70B Cost | Winner & Mechanism |
|---|---|---|---|---|
| RAG Summarization | 8:1 Input-Output | $0.00625 | $0.00088 | Llama 3.1 70B wins; input-heavy calls amplify GPT-4o's $2.50/1M input premium, widening the gap beyond 7x. |
| Long-form Generation | 1:2 Input-Output | $0.00375 | $0.00088 | Llama 3.1 70B wins; output-heavy calls favor GPT-4o's cheaper input side less, narrowing the gap to ~3x. |
| Batch Offline Classification | Async Batch API | $0.00175 | $0.00088 | Llama 3.1 70B wins on price; GPT-4o Batch ($1.25/$5.00 per 1M) narrows the gap to ~1.8x but cannot undercut hosted inference. |
| Cached Conversational Pilots | >70% Cache Hit Rate | $0.00132 | $0.00088 | GPT-4o achieves price parity within 1.5x; cached input at $1.25/1M neutralizes the input penalty for stateful dialogues. |
Cost tables routinely omit the latency dimension that dictates pilot throughput. According to Groq's published serving benchmarks, LPU-based inference delivers approximately 300 tokens/sec for Llama 3.1 70B compared to GPT-4o's 80–100 tokens/sec. In interactive pilots where wall-clock time gates user experience, this threefold speed advantage reduces operational friction and allows higher concurrent concurrency without proportional infrastructure scaling. For teams measuring success by user engagement duration rather than pure token economics, the latency multiplier makes Llama 3.1 70B the superior choice even when GPT-4o approaches price parity via caching.
Sticker pricing is a static snapshot; enterprise pilots operate in dynamic workloads where caching, batching, and self-hosting amortization compress the gap between GPT-4o and Llama 3.1 70B to under 2x. However, the canonical decision rule—run Llama 3.1 70B unless GPT-4o exceeds it by >5 points on your eval set—carries structural blind spots that can invalidate budget assumptions if treated as universal law. The data does not capture three critical failure modes: evaluation latency artifacts, variance in hosted endpoint stability under burst traffic, and the hidden cost of quality regression when forcing suboptimal models into production pipelines.

What the Data Doesn't Tell You
Variance across cases emerges from how different workload classes interact with model architecture. For retrieval-augmented generation (RAG) pipelines with high prefix repetition, Llama 3.1 70B's cached input discount creates a non-linear cost curve that collapses the price gap faster than linear projections suggest. Conversely, for creative synthesis tasks with low prefix overlap, GPT-4o's output efficiency advantage dominates, and the blended cost ratio reverts toward the 5x sticker baseline. This means the "correct" model depends not just on quality delta but on your token distribution profile. If your pilot involves more than 60% unique prompts per session, the caching benefit for Llama 3.1 70B diminishes, and the premium for GPT-4o becomes harder to justify even with moderate quality gains.
| Evaluation Artifact | Mechanism | Budget Impact |
|---|---|---|
| Latency-induced truncation | GPT-4o's lower inference latency reduces timeout errors in synchronous call chains, inflating effective completion rates vs. Llama 3.1 70B | Pilot metrics may overstate GPT-4o reliability by 8–12% in high-throughput workflows |
| Caching asymmetry | Llama 3.1 70B prompt caching discounts apply only after repeated identical prefixes; GPT-4o lacks equivalent enterprise cache tiers | First-run costs for Llama 3.1 70B remain near sticker until cache hit rate exceeds ~30% |
| Self-hosting variance | Amortization assumes stable GPU utilization; idle capacity during pilot phases skews per-token costs upward by 40–60% | Self-hosted Llama 3.1 70B appears 2.5x cheaper than GPT-4o only at >90% cluster utilization |
The canonical rule breaks in two specific edge cases where paying the GPT-4o premium is justified despite a quality delta below 5 points. First, when your evaluation set fails to capture hallucination sensitivity in high-stakes domains like legal or medical triage, GPT-4o's superior factual grounding may reduce downstream review costs by 20–30%, offsetting the token premium. Second, when integration complexity favors OpenAI's ecosystem—such as native tool-use schemas or lower-latency requirements for real-time user-facing applications—the total cost of ownership shifts. In these scenarios, the quality delta metric is insufficient; you must factor in engineering hours saved and risk exposure. The rule holds for standard text-generation pilots but fractures when operational constraints or domain-specific risk profiles dominate the decision matrix.
To avoid misallocating pilot budgets, verify your workload's token distribution and latency requirements before committing to the canonical rule. Run a parallel test with both models on a representative subset of your actual traffic, measuring not just quality scores but cache hit rates, timeout frequencies, and end-to-end latency. If Llama 3.1 70B meets your quality threshold and your workload exhibits high prefix repetition, the hosted endpoint remains the optimal choice. Only escalate to GPT-4o when the data reveals a clear operational or quality deficit that the price sheet alone cannot predict.
| Edge Case | Condition | Action |
|---|---|---|
| High-stakes hallucination risk | Eval set lacks adversarial fact-checking; downstream review cost >$0.002/token | Prioritize GPT-4o regardless of quality delta; audit eval coverage before scaling |
| Real-time latency constraint | User-facing application requires <800ms p95 response time; Llama 3.1 70B exceeds threshold | Accept GPT-4o premium; measure latency impact on conversion/retention metrics |
| Low cache hit rate | Unique prompt ratio >60%; caching discount yields <15% savings on Llama 3.1 70B | Revert to sticker ratio analysis; GPT-4o may be cost-optimal if quality delta <3 points |
Artificial Analysis composite scores aggregate benchmarks into a single metric, but per-task variance is wide. On multi-step reasoning and instruction-following edge cases, GPT-4o outperforms Llama 3.1 70B by 15+ points on some evals while trailing on others. This means a pilot's actual quality-adjusted cost can differ from the composite by 2x in either direction depending on your specific task mix. A council comparing per-1K prices without measuring tokens-per-task gets the wrong answer because models differ in verbosity. Side-by-side generation tests show GPT-4o tends to produce 10–30% fewer output tokens than Llama 3.1 70B for the same task prompt. A per-token price comparison understates GPT-4o's effective cost advantage on output-heavy tasks; when you account for the token delta, the blended cost gap narrows significantly before discounts are even applied.

What the Price Sheet Hides
The self-hosting uncertainty band further complicates the math. The $0.0002–$0.0004 per 1K floor assumes 60% GPU utilization and FP8 quantization with no quality loss, but real deployments report 30–50% utilization on bursty pilot traffic and occasional FP8 degradation on sensitive tasks. This can push true self-hosted cost per 1K above the $0.88 hosted rate below ~1B tokens/month. The crossover volume is an estimate with a ±50% error band, not a constant. Furthermore, both OpenAI's GPT-4o rates and Llama provider rates have changed multiple times since 2024. OpenAI cut GPT-4o input pricing and introduced caching mid-cycle; Together AI and Fireworks have both adjusted 70B rates. Any 2026 pilot budget built on today's sheet needs a ±20% price-drift contingency line.
| Factor | Mechanism | Budget Impact | Decision Rule |
|---|---|---|---|
| Quality Variance | Per-task score swings ±15 pts vs composite | Quality-adjusted cost deviates 2x from sticker | Run shadow pilot only if quality delta >5 pts favors GPT-4o |
| Output Inflation | GPT-4o saves 10–30% output tokens vs Llama 70B | Effective GPT-4o cost drops relative to Llama on verbose tasks | Measure tokens-per-task; do not rely on per-1K rates alone |
| Prompt Sensitivity | Llama needs re-engineered prompts (+20–40% input) | Erodes Llama's input-cost advantage in practice | Include prompt-tuning overhead in pilot budget |
| Self-Host Floor | $0.0002–$0.0004 assumes 60% util, FP8 no-loss | Real 30–50% util pushes cost above hosted rate below ~1B tokens | Treat crossover as estimate with ±50% error band |
| Price Drift | Rates changed multiple times since 2024 | Static budgets fail within quarters | Add ±20% contingency line to all 2026 pilot forecasts |
Finally, surface the hidden pilot cost neither price sheet captures: evaluation and routing overhead. Running both models in a shadow pilot doubles inference spend during the comparison phase. Prompt-format sensitivity means Llama 3.1 70B often needs re-engineered prompts—system-prompt tuning, few-shot additions—that add 20–40% input tokens, eroding part of its price advantage in practice. The myth that Llama 3.1 70B is always 5x cheaper than GPT-4o holds only for uncached, synchronous, output-heavy calls. For cached, batched, or self-hosted workloads above roughly 2B tokens per month, the ratio reverses. Your pilot must measure the total cost of ownership, including eval infrastructure and prompt engineering, not just the API meter.
Enterprise pilots rarely mirror static price sheets, and the 2026 budgeting trap is treating list rates as binding constraints. Consider a concrete 12-week RAG summarization pilot: 50 million tokens processed at an 8:1 input-to-output ratio (44.4M input, 5.6M output), running synchronous traffic with a 40% prompt-cache hit rate on the GPT-4o side, while Llama 3.1 70B is served through Together AI. The arithmetic here exposes how caching mechanics and model-specific overheads rewrite the sticker ratio before production scales.

Worked Case
GPT-4o’s line-item calculation follows OpenAI’s published metering structure. Input costs $111.00 at list ($44.4M × $2.50/1M), but the 40% cache hit reduces that segment to $83.25 using the cached tier at $1.25/1M. Output remains uncached at $56.00 (5.6M × $10.00/1M), yielding a total of approximately $139.25 for the pilot window. If the workload qualifies for the Batch API, both lines halve, dropping the total to roughly $69.63. This demonstrates why synchronous-only billing overstates true enterprise spend when historical context repeats across sessions.
Llama 3.1 70B presents a flatter cost surface on Together AI: 50M tokens × $0.88/1M equals $44.00 flat, with no caching or batch tiers to compress further. However, the realistic figure requires accounting for prompt-re-engineering overhead documented in earlier sections. Adjusting input by +25% to compensate for system-prompt expansion pushes input to 55.5M tokens and total volume to 61.1M, raising the bill to $53.77. The gap between models narrows from a theoretical 5x to a practical 2.5x once operational friction enters the ledger.
Quality adjustment determines whether the premium justifies itself. Assume your internal eval set shows GPT-4o scoring 6 points higher on a 100-point summarization rubric against Llama 3.1 70B’s baseline. Dividing raw cost by rubric score yields $1.70 per quality point for GPT-4o ($139.25 ÷ 82) versus $0.71 per point for Llama ($53.77 ÷ 76). Despite the measurable delta, Llama still wins on cost-per-quality. The canonical rule applies cleanly here: because the 6-point gap exceeds the 5-point threshold, you pay the GPT-4o premium for the pilot phase. The incremental cost sits at $85.48 over 12 weeks (~$7.12/week), functioning as cheap insurance for a production decision. Scale that same math to 50x monthly volume, however, and the $8,548/month incremental flips the recommendation back to Llama unless the quality delta persists under load.
The myth that Llama 3.1 70B is universally five times cheaper collapses under cached, batched, or self-hosted workloads above two billion tokens monthly. Budget against mechanism, not margin. Route to GPT-4o only when your eval set forces it; otherwise, keep Llama on the endpoint and reserve the premium for production scaling where the quality delta actually compounds.
| Model | Pilot Cost (Synchronous) | Pilot Cost (Batch) | Adjusted Quality Score | Cost Per Rubric Point | Verdict |
|---|---|---|---|---|---|
| GPT-4o | $139.25 | $69.63 | 82 | $1.70 | Premium justified only if delta > 5 pts |
| Llama 3.1 70B | $44.00 | N/A | 76 | $0.71 | Baseline for hosted endpoint routing |
| Incremental Delta | $85.48 | $25.63 | +6 pts | $0.99 | Acceptable for 12-week validation |
Enterprise pilots routinely fail their first budget review because procurement teams price against static list rates instead of the dynamic mechanics of actual inference workloads. The 2026 pilot budget must be structured around five operational rules that force cost comparisons into reality before capital is allocated.
Five Rules for the 2026 Pilot Budget
Rule 1 — Budget on blended, How does OpenAI's Batch API discount change the effective pricing for GPT-4o workloads? The Batch API applies a fifty percent reduction to standard rates, dropping costs to $1.25 per 1M input tokens and $5.00 per 1M output tokens. At what monthly token volume does self-hosting Llama 3.1 70B become cheaper than cloud inference? Self-hosting becomes economically dominant at scale beyond approximately two billion tokens monthly when amortization erodes the hosted endpoint premium. What specific GPU configuration and utilization rate establish the cost floor for on-premises Llama 3.1 70B serving? Serving FP8 Llama 3.1 70B requires roughly two 80GB GPUs like H100s at sixty percent utilization, establishing a floor near $0.0002 to $0.0004 per 1K tokens. Why do raw text comparisons between GPT-4o and Llama 3.1 70B often misrepresent true token costs? Tokenizer variance causes identical source documents to tokenize five to fifteen percent differently across models due to GPT-4o's o200k_base vocabulary versus Llama 3.1's 128K vocabulary. Which provider offers the lowest flat rate for Llama 3.1 70B without input-output asymmetry? Together AI lists a flat rate of $0.88 per 1M tokens, while AWS Bedrock charges $0.99 per 1M with uniform pricing that removes input-output asymmetry. What performance delta allows enterprise pilots to absorb Llama 3.1 70B's lower blended rate without rework? Llama 3.1 70B scores within roughly ten to fifteen percent of GPT-4o on aggregated reasoning and coding evals, making the quality gap narrow enough for most pilot tasks. Also worth reading: Llama 3 8B Extending Context to 500M Tokens - Implications for Enterprise AI: Llama 3 8B Extending Context · Benchmarking Mistral Medium A Data-Driven Comparison with GPT-4 in Enterprise Applications: Benchmarking Mistral Medium A Data-Driven · Benchmarking Mistral Medium A Technical Deep-Dive into Performance Metrics Against GPT-4: Benchmarking Mistral Medium A TechnicalFrequently Asked Questions
Quick answers
What is the blended cost per 1K tokens for GPT-4o at a standard 3:1 input-to-output ratio? At a standard three-to-one input-to-output ratio, GPT-4o registers a blended rate of $0.0044 per one thousand tokens. How does OpenAI's Batch API discount affect GPT-4o pricing? OpenAI's 50% Batch API discount applied to standard rates yields a blended cost of $0.0044 per 1K tokens and halves each figure from the published baseline. What monthly token volume threshold makes self-hosting Llama 3.1 70B economically dominant over cloud inference? Beyond approximately two billion tokens monthly, running Llama 3.1 70B on-premises inverts the cost curve entirely compared to cloud inference. Why do raw sticker prices misrepresent the true cost gap between GPT-4o and open-weight alternatives like Llama 3.1 70B? The apparent fivefold disparity collapses when accounting for OpenAI’s fifty percent batch processing reduction, cached-input pricing tiers, and asymmetric conversation flows that compress effective pricing. How does tokenizer variance impact budget comparisons between GPT-4o and Llama 3.1? Identical source documents tokenize 5–15% differently across models due to GPT-4o using the o200k_base vocabulary versus Llama 3.1's 128K-vocabulary tokenizer, requiring normalization on identical tokenized inputs to avoid mispricing.