Choose a meaningful denominator
A cheap response that needs repeated correction can be expensive at the workflow boundary. Record the number of attempted tasks, completed tasks and accepted results separately. Comparisons must use the same definition of accepted work and the same measurement period.
Expose the full cost boundary
Include the model calls, retrieval or tooling charges, application runtime, review, rework and a clearly stated allocation of fixed operating cost. Avoid mixing contracted rates from one service with public list prices from another. Microsoft’s cost documentation makes the dependent-service boundary explicit; the site’s model uses supplied rates rather than current quotations.
Use a scenario, then measure
Our Outcome Economics tool estimates a monthly scenario and cost per accepted completed task. It is arithmetic, not a forecast of adoption, quality or savings. Replace the illustrative assumptions with measured pilot data and reconcile the estimate against actual operating costs before making a commercial decision.