I'm trying to buy a 50-55 in tv on a budget (under $2000). I have no idea where to start. I'm thinking about buying something used from the classisfied ads. Would I be better off with a new low end set? Has the technology improved that much in the last 2 or 3 years? We watch mostly digital cable. What should I look for/stay away from in a used set? Any advice would be sincerely appreciated. Thanks.