Check pricing provenance before trusting a model cost estimate

A model receipt can contain a nonzero dollar estimate even when its pricing basis is unknown. Before ranking cheap-model routes, retain that basis and check the estimate against current model-specific rates using explicit assumptions about input, cache writes and output. Preserve the original CLI estimate separately from an illustrative API calculation and actual billing. A discrepancy identifies an unqualified estimator, not its cause or the account's charged cost. Token counts and a model name alone cannot establish that the harness used the correct pricing table.

Applies when: Claude Code or another model harness reports costs for a newly available model. Keywords: Claude Code model pricing costBasis unknown estimate cache output billing