So long as everyone who wants to play a game can purchase it used, its functionally no different than piracy. Except someone who did no work makes money off of it.

If a game can't be easily legally obtained, if at all, its a pretty common belief that piracy is justified in the name of preservation.

The only exceptions to this are new releases which haven't reached critical mass, and smaller releases which will never reach any sort of mass following.

The former is especially important when you realize that two months post-launch of a new piece of media, the company has made back the artist saleries, and everything after that is just bonus for the useless vultures upstairs.