Seriously depends on the game. Black Ops 2 for example, a game that came out over a decade ago, still costs $100 on steam (assuming you want the DLC). At best you'll get it for $50 during sales. The fact that, even during a sale, a game with a completely dead playerbase costs as much as a modern title is absolutely nuts.

A lot of games are like this, unfortunately. Not everyone takes advantage of sales because many people are going to end up buying the game regardless.