I think that if you consider yourself a "real" gamer, you should own more legit copies than used copies.  I've got a couple of used games but I usually buy them new, even if it means I have to wait a few months until the price is decent.  You should want to support people who make good games so that more good games get made.  At the least, don't buy them used from Gamestop.  Those guys are human garbage at its finest.

A "real" gamer who owns nothing but used copies of games sounds like a music 'fan" who doesn't own a single legit copy of albums that his favorite band makes.