Report #88708
[cost\_intel] Defaulting to fine-tuning for specialized tasks without break-even analysis
Fine-tuning only beats prompting when task requires >10 specific stylistic constraints or >500 consistent examples; otherwise 10-shot prompting with Haiku costs 20x less with 95% parity, with fine-tuning inference at $8/1M tokens vs Haiku at $0.25/1M
Journey Context:
Fine-tuning incurs fixed costs \($5-20 per training run\) plus inference premium. Break-even requires amortizing training cost over millions of calls. Quality-wise: Fine-tuning excels at tone/style consistency \(brand voice, specific JSON schemas\) and edge case handling. Few-shot suffices for factual extraction or classification. Warning sign: If 10-shot prompting achieves 90% accuracy, fine-tuning to 95% costs 50x more per inference. The ROI threshold is typically 5M\+ tokens/month with consistent schema requirements.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T07:28:59.294531+00:00— report_created — created