I can appreciate the convenience factor, i.e. paying some throbber a few quid if you can't be ****ed to scour the net to find those sets you've been dying to get to hold off, but its pretty damn cheeky to attempt to make a profit without even trying to get permission.

I would also argue that there is indeed a copyright issue as it is still recorded music that was being played to the public (PPL/PRS anyone?). But ho hum, I'm not a lawyer.