Look, I rarely (if ever) buy games on steam if they're not on sale either. With very few exceptions (Christmas sale for Gods and Kings to name one), the games I buy for sub 10 bucks are never under a year old. So, you're not buying a new game.
This is an issue. The whole reason these games are no longer ~$50 is because they're old. If we make it a habit of only purchasing games a year old, how the hell can developers hope to recoup their development costs? What a proposition: Spend millions of dollars on a game, and don't expect to recoup any of that until a year after you release it. Talk about shitty cash flow.
Though, there is one giant assumption in my statement-- The assumption that games have to be sold around $50 new. Personally, I reject that idea, and feel that $40 or $30 is a much better proposition, depending on the game. If you're not making a AAA game that has a huge fan-base like Call of Duty, Battlefield, Assassins Creed, or Halo, you probably shouldn't be charging the full $50 (well, since I mentioned console games, I guess it's really $60). This would make your game more competitive. Sure, you can get the yearly rehash of the same game you've been playing for the better part of a decade, or you could get two games from either a totally new franchise or one you haven't tried yet for the same price instead. I feel the market would be a lot more competitive if this were the case, but that's just my opinion.
Also, I'm fairly certain Sony/Microsoft/Nintendo set minimum release prices in order to be approved for release on their systems, but if so, that's their failing.