What Backup Camera Should I Buy?

2 months ago I bought a very cheap (about $15) Koolertron backup camera. It is now starting to go out.... I would like to buy a new one but I don't really know what brand to go with. The one that I have now screws onto the license plate, but I would really like an under mount model (above the plate). And by the way I do not really want to spend more than $50... any ideas???