Used DLP tv's can be a diamond in the rough. You can get 50"+ for $250 or under and have 98% of the picture quality of a LCD or Plasma. Some would say even better, but that's subject to debate. First look up the native resolution. That does make a difference when you get TV's that big. Don't shy away from a 720p native resoltion, it is still an awesome picture, just don't pay as much for it. AT BEST his TV is worth $250, that being a true 1080p with very low bulb hours. Next do a cold start turn on with the TV. DLP's take a good minute to warm up fully but look for any hazing of the screen or blotches of different colors. That will be a sign of the optical engine going bad. Also listen for unusual spinning sounds. If there are it could be as simple as the fan in the back but could also be the color wheel.