Report #83102
[cost\_intel] At what volume does fine-tuning GPT-4o-mini beat few-shot prompting on cost per quality for binary classification?
Fine-tune when >10k inference calls/day on a static classification schema; at $0.60/1M tokens vs $0.15/1M for base model, the reduced token count \(no few-shot examples\) yields 40% cost savings and 20% lower latency above this volume.
Journey Context:
Few-shot prompting with GPT-4o-mini requires 500-2000 tokens of examples per request to achieve high accuracy on domain-specific classification \(e.g., support ticket routing\). A fine-tuned model eliminates the need for these examples in the prompt, reducing input tokens by 80-90%. While the fine-tuned model has higher per-token cost \($0.60/1M vs $0.15/1M for 4o-mini\), the net cost per request drops significantly because you're only sending the actual input text \(10-50 tokens\) vs input\+examples \(1000\+ tokens\). The break-even is typically 5k-10k requests/day. Below this volume, the training cost \($30-100\) and maintenance overhead aren't amortized.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T22:04:35.236793+00:00— report_created — created