Yes, I would agree, $50 is a bit overpriced for a 3.5" that only supports SUB2. I picked up this
oneIt was about $37 with free shipping when I got it. GMG has some decent enclosures. The reason for the high price there was that it's a SUB2/Firewire combo enclosure, so I can float in and out of any connection that I might need. Yeah, it has a bit of baling, but the case is pretty solid on all sides (the aluminum sticks out so if you drop it on edge you just bend that instead). I've been pretty happy with it.
I'd say for 3.5" SUB only you're range should be 20-30. SUB/Firewire should be 30-50.
There are always sales on this kind of stuff.