| I would suggest one of the Fender acoustic electrics. Good bang for the buck. Blueridge also makes one heck of a guitar for not alot of dough. It was my first steel string, still own it, and still think it can give a factory guitar (like a martin) a run for it's money IMO. Though my Santa Cruz eats it and most Martins for lunch (also IMO).
Yamahas are also very good for the price. I would also scour the used market for an 80's/early 90's sigma by martin. Great guitars for the money, and they are out there often on CL and the bay. Most don't have electronics, but you can pick one up for $300, spend the rest of your budget on an LR baggs, and be ready to pick.
Your main concerns should be non-laminate construction and the quality of the pre. Though fancy tops are pretty (like the Ibanez acoustics), a good acoustic top uses some variety of spruce (or mahogony), and those fancy tops are typically laminate (tone killers). You also probably want to stick with back and sides made of either rosewood, mahogony, koa, or sometimes maple. I personally would avoid a cutaway also; I have never heard a cutaway that sounded as full as a standard OM or D body.
Acoustic Guitar shopping is one of my favorite activities and I have spent much time and research in the pursuit of the "one." It can turn into an expensive habit; $3000 guitar, $35+ picks, $100 capos, $30 strings, etc. The more you research and spend initially the better off you are when you start saving and waiting for your next box.
Regards,
Mike | 
