You are likely to have more repair problems and performance will not be as good. The margin in TVs has shrunk so that you can get a good deal from the major companies. I got a 42" 1080 Panasonic Plasma for my wife for $900 this fall, you should do better now. I don't think it is worth the gamble.
Off brand hdtv sets.....
Are brands like Dynex, INsignia,etc high risk or do they compete with brand names like samsung,toshiba,etc? Im looking at spending 1k or less on a set...leaning towards panasonic...but there are some tempting deals on off brands...