I currently play a Fender Accustic Bass which has integral pickup etc for playing "Pluged or Unplugged". (Sorry I dont have a model name or number, Guitar not with me at the moment and I never bothered looking before!) I have found it a robust instrument capable of giving a remarkably loud and full sound when played unplugged and it also sounds good through an amp though I rarely play it plugged in. It cost me £350 in 2000 in the UK which should bring it into your price range and US prices for guitars are usually substantially cheaper for the same instrument bought in the UK. It certainly gets my recomendation after lots of hard use though I am sure there will be others worth considering. Good luck, let us know what you decide.