I used to buy games at full price or just get them as gifts when I was younger. Now that I'm a bit older, I am much more careful when choosing which games to buy and how much they cost.
Today games are generally $60 at launch. I think that's too high for a single player game with just a story mode unless the game is 30+ hours long. I normally wait for a price drop with this type of game. For example, Super Mario 3D World only has a story mode. While it's multiplayer, it's still story only so I traded in some games and got the price down to $15.
Yet, with Pikmin 3 I paid full price. I knew I'd play it multiple times eventually and that it had a mission mode for added value.
The type of game matters as well. For example, a multiplayer focused game like Mario Kart, Smash Bros, or LittleBigPlanet I have no issue paying full price for. A 3D platformer or Adventure game should be $50 and a 2D game should only be $40 or less in most cases for me.
Then you have HH games which I think should have a max price of $40 from the get go. Although, the majority should be priced at $30 IMO.