When Fine-Tuning Makes Economic Sense (And When It Doesn't)

The Fine-Tuning Decision

Fine-tuning makes sense when: you need domain-specific accuracy >95%, your query volume exceeds 10K/day, prompt engineering reaches diminishing returns, or you need latency under 200ms.

Fine-tuning does NOT make sense when: query volume is low (<1K/day), requirements change frequently, training data is insufficient (<10K examples), or prompt engineering achieves adequate results.

Calculate breakeven: fine-tuning cost / (prompt_engineering_cost_per_query - fine_tuned_cost_per_query) / daily_queries.