Hey fund, I was in the same place as you about a year ago after doing brush painting for like twenty years. What I did comes under your budget, and I couldn't be happier with my set up;
Iwata HP-CR and
Senco PC1010 compressor, if bought from amazon should come to under 250.00. If the hose is like mine you'll need a connector between the compressor and the hose, but thats a $2 part from a local hardware store. The Airbrush is really forgiving and a good all-around brush; I actually prefer it over my Eclipse. Its dual action as well.
The compressor has its own regulator but doesn't have a moisture trap, thats a few more dollars if you want to spring for it but I don't have one and I seem to do fine in my climate. Its got a sizable tank, is quiet and that regulator allows you to do a wide array of pressure settings. The senco is a keeper that you can use to upgrade with a wide range of airbrushes.
All in all this set up allows you to do everything you might want to do with an airbrush, without much compromises. The only limitation might be really fine lines but even that you can do in a sinch. I can't recommend it more, as it really rekindled my love of the hobby.