I work for a hedge fund (where I used to be a full time employee), and I have 15 years experience, so the pay is very good. I don't know about other companies, but if a US company is willing to pay 250k to US employees - meaning they also pay their health insurance, stock options and other perks so it must cost them around 300k - there is no real reason why they wouldn't hire you at 200k. As a company owner, you'd have to pay for national health insurance (at least, that's how it works in France), and then income tax of course. Overall you'd pay about 50% in taxes, which is about the same as what you'd be taxed in New York if you factor in health insurance cost. So overall being able to get 100keuros take home income is definitely doable, and you're confortable, given the rent in Paris is about half that of New York.
Biggest problem is time difference. Working for companies on the East coast is way easier than West.
Good luck