Cheaper tokens, bigger bill

A team ran an AI cost-routing layer for four months, then shut it off. The savings had not vanished. They had moved to a budget nobody was measuring.

Same model, ten times the bill

A cached token costs a tenth of a fresh one, and coding agents hit cache most of the time. Your AI cost curve is an engineering choice, and most teams make it by accident.

Your model was never your moat

Open-weight models now match frontier quality at a fifth of the cost. For anyone building on AI, that shifts where durable advantage has to come from.