For what age?

Let's say 18-25.

£1000-2500/month

This (as a minimum).

I live off of $200 a month

Too broad.

18 would typically be in college and with little work experience.

25 would be out of college and have work experience.

If I made what I did at 18 right now, I'd be ahead of 99% of 18-year-olds

depends where you live really

Depending on the city?

25k for a single person in the Southern US is enough.

In major urban areas you need like double that to survive though, I heard NYC, Californian cities and Miami are expensive.

This

25k in most cities in America. You can survive off of that in NYC. You'll just have to live in the Bronx with a roommate to afford rent. Its fine though.

Double that and you can afford your own car, healthcare, house/apartment, etc.

You're poor if your annual income is less than 100K