I had the Pansat 2500 and the 3500, they are pretty much alike, component out on the 3500, rca on the 2500. It does a nice blind scan but if you just want it for amc3 it should be fine. Of course you won't be able to watch PBS HD with it. As for the $50 price, well, I wouldn't pay any more than that, there are other newer receivers you can get for the same or less.
I agree with starman on this one. I have a 2500 and it is the most stable workhorse I have in a satellite box. If you are concerned about the price, you may find others cheaper, but if you want one that has good blind scan and motor support, $40-50 would do you fine in that category.