What bugs me the most about this is not buying used games, but selling my games so I can buy new games. I don't buy used for many reasons, but it helps to buy new games with the credit from trade ins.
Also, I don't mind supporting developers who've created/designed a game, but $70 new, especially without physical media possibly, that's a bit much. If its a download the price should stay at $60 or lower cause they won't have the cost of making and distributing the discs and having the middle man get a cut too, I.e. best buy, target, etc.