- Define acceptance
- Count complete costs
- Count accepted outcomes
- Compare
- Review quality
A cheap request can create an expensive result
A model price tells you what a unit of service costs. It does not tell you what a completed business outcome costs. A low-price model that needs more retries or extensive review can be less economical than a higher-price model that reliably completes the same bounded task. Keep quality and risk acceptance criteria constant before comparing alternatives.
Define the denominator first
Choose an outcome that the business can accept: a reviewed case summary, a correctly routed request or a validated document extraction. Count accepted outcomes over the same period and scope as the costs. Do not use all API responses as the denominator if some were abandoned, rejected or repeated.
A deliberately small worked example
For one period, suppose 1,000 attempts cost $80 in model usage, $20 in retrieval and $100 in attributable review. If 800 outputs pass the agreed acceptance gate, the cost per accepted outcome is $200 / 800 = $0.25. Dividing by attempts would report $0.20 and conceal the effect of failures. These are synthetic inputs, not a vendor rate card or savings claim.
Keep the cost boundary explicit
Include retries, supporting services and directly attributable human review where measured. Treat shared platform cost consistently. Document exclusions such as sunk implementation cost rather than silently changing the boundary between options. Distinguish variable operating cost from fully loaded cost when presenting the result.
Use economics with control evidence
A lower result is not approval to release. Compare the accepted quality threshold, authority limits and material failure behavior alongside cost. If no outcomes are accepted, cost per accepted outcome is undefined; do not report zero. Investigate the failed workflow before expanding its capacity.
Source context
Methods can be adapted internationally. The paid collection’s jurisdiction-specific operating guidance centers on the United States and Canada; apply local requirements and actual contracts. Examples are illustrative, not guaranteed savings or certification.