The problem with buying a tv online is that if there is a problem with the TV, then you have to contact the place that sold it online to get a refund or exchange it. Then you get to play the shipping game, we all know thats a fun game. Make sure it is a reputable place that will actually take care of you.
I would gladly pay a little extra to be able to take a tv into an actual store if I had a problem.
I actually had to take 2 brand new TVs back to best buy one time because neither of them worked. I would have been pissed if I would have had to ship two TVs back to some online place that might not cover shipping and then wait a few weeks for a new one.
