If plans were at cost and API pricing was marked up that would mean there’s a 90%+ profit margin on tokens and instead of raising money and talking about revenue, Anthropic and OpenAI would be talking about their obscene profits.
[1] the caveat is that the average plan user probably doesn’t use all of their quota, I guess maybe 30% is the average across all users.
The fact that Anthropic is rumoured to have a profitable quarter indicates that their margins on API priced inference are very strong.