I would like to recommend you a LG 3D TV if you are looking for the best passive 3D TV that are LED lit. There are only a few companies who use passive 3D technology, LG, Toshiba and Vizio. However, I don't want to recommend you a Vizio because their TVs are crappy. Their TV doesn't produce good 3D pictures like Samsung or LG, and I also read a review saying their TV usually breaks down within a year and hard to fix due to parts not available in the U.S. Among the passive 3D TV manufacturers, LG is the best. Besides, it fits into your price range, including 4 pairs of 3D glasses. I think LG 3D TV is quiate affordable if you get it under 47"