It really depends on where you go and what kind of paint you get - good factory-quality paint is much more expensive than cheap body shop paint, and the price will vary based on what color you want, how many clearcoats you want, if it needs any preparation body work first or if there's rust on the body, and it will cost even more if you get fancy paint with metallic flakes or two-tone colors or anything fancy like that.
I'd say, for a factory-quality paint job, in a common color without anything special added, you're looking at $2000-3500.
However, if you just want a cheap paint job that looks okay without any major body work, you should go to Maaco or Earl Shieb paint shops, they're everywhere and you're only going to pay probably about $700 or so - I got my car painted there and I was very happy with how it turned out