It's interesting that the API token cost of GPT-5.5 is double the cost of GPT-5.4, but Copilot charges a 7.5x multiplier and gates the model in premium plans. Clearly, they severely underpriced previous models like GPT-5.4 which they sell at $0.04 per request -- and these models can of course work for 30+ minutes in response to a single request and incur costs of several dollars.