Peerflix has always credited me for bad disks I received, though they were more obviously bad than "stops playing after 44 min" though the latter is actually more frustrating.

That it is just the disk and no case I think is pretty clearly laid out (especially since until recently almost all people started by putting disks in, not by buying them.) The postage is a usually a single stamp, so how can half.com be lower?

But yes, you do take the risk of a bad disk and having to file a claim, which is a pain. That you don't get the case is considered a feature, to keep mailing costs down.