In the rare event of me buying some DRM protected content (rare ebooks, for example), I will usually do whatever is needed to strip it for my own archival purposes, and share with friends. When something is DRM-free (Humble bundles come to mind) I won't share it, but send my friends to the provider. That's just the little rebel in me.

That's what I meant about the economics of it. Of course, that's only part of the picture. It's true that resale value must figure into the new value, but it also might depress demand for new sales.

Coming at it from another angle, Gamestop makes a lot of money from second-hand sales. That's money that the game and console makers don't get to make and they want it.