Yeah it seems insane that it's priced this way to me too. Using sonnet/opus through a ~$40 a month copilot plan gives me
at least an order of magnitude more usage than a ~$40 a month claude code plan (the usage limits on the latter are so low that it's effectively not a viable choice, at least for my use cases).
The models are limited to 160k token context length but in practice that's not a big deal.
Unless MS has a very favourable contract with Anthropic or they're running the models on their own hardware there's no way they're making money on this.