It hasn't. I've only bought ~4 games at full price the last decade, now I just wait for them to be around $20. The $70 price seems to be more focused on cashing in on people that buy on release, but prices go down all the same only like one year after release.
Games that have fallen to $20 also have the nice advantage of having most of their bugs worked out and the vast majority of the balance passes complete. It's easily the best time to buy and play a game.