Every model's pricing page shows one number you are meant to compare: dollars per million tokens. Put two side by side and one looks cheaper. That comparison is broken - and if you build with an AI coding agent, it is broken in the most expensive direction. The price is per token, but a "token" is not a fixed amount of text: each model's tokenizer cuts the same file into a different number of pieces, and you pay per piece. Here is the number that lands on your invoice. The exact same TypeScript ...