Report #74127
[cost\_intel] Fine-tuning ROI negative below 100k monthly request threshold
Fine-tune only with >50k training examples AND >100k monthly requests; otherwise use 5-shot prompting with GPT-4o-mini.
Journey Context:
Fine-tuning costs $0.80-4.00 per 1k tokens to train plus inference at base rate. A fine-tuned 4o-mini is 3x cheaper than base 4o but requires $500-2000 training cost. Break-even occurs at ~100k requests/month where inference savings \($0.60 vs $0.02 per 1k tokens\) recoups training in weeks. Below this volume, training cost dominates. Quality signature: fine-tuned small models fail on out-of-distribution inputs \(distribution shift\) where large models generalize; monitor for confidence collapse on edge cases.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T07:01:11.969882+00:00— report_created — created