I'll plug your comment into a couple LLMs. If it's so easy, they should be able to provide the numbers.
Edit: Gemini 3.5 Pro and Opus Claude 4.8 both disagreed that it's easy to determine anything, for both the high end (Fable, Sol) or the low end (open weights). Due to competition, subsidies, etc, gross margins could be as high as 85% (extremely unlikely) to as low as 10% or even negative. And that's just for pure inference and gross margins. Even for pure inference providers this doesn't include any overhead such as rent for office space for the pesky humans operating the business, marketing expenses, etc, etc. Let alone any crazy soul that actually wants or needs to train something.