I made my own screen using screen (ie canvas) material purchased on ebay (many vendors offer it there). I bought it a couple of years ago and think it cost about $20 or so. It's a hi-quality material that is stretched on a frame constructed of 1x2's with 1/4" masonite corner reinforcement. The screen is 92"x52" and cost me about $30 total and an hour of my time to construct. It works great.
Looking at the "paint on" options above, I can see advantages to them, in my case since my home theater has been a work in progress during the last 2 years, it's been handy being able to move the screen whenever I rearanged things.
The other recommendation I'd offer is given your budget should buy you a good quality screen (unless you're after motorized), do your research. When I bought mine I was experimenting with home theater/projection, and specifically wanted to keep the $ to a minimum. If you're not experimenting, do your research as suggested above by others. While mine is a very good screen and I'm happy with the results, I'm at a point now that I'm looking for something more SOA.
As for projectors, not sure what your budget is, but make sure it's native resolution is 720P minimum, AND that it's super quiet. I have a Optoma HD70 which is both and I'm extremely happy with it, and impressed given it cost <$900.