I agree with the record companies on this one (I know I'm one of the few). I don't believe buying a product gives you the write to duplicate it and use those duplicates any way you see fit (in the case of CD's often times selling the duplicates).

If you buy a CD you have the write to play that CD and even re-sell that CD (the actual CD purchased not a copy) if you like. Making unauthorized duplications is or at least should be illegal.