If you're only asking the people who regularly buy the games at full price, why bother asking at all? Obviously they feel it's worth it or they wouldn't be buying them. That's like asking, "Of the people who like McDonalds the best, who likes McDonalds the best?"
I don't buy games new if they're full price, I wait until they get very cheap. There are certain games I've bought once they got to $19.99, but I really wanted those games very badly. Usually I now limit myself to $5-$10 for games that are current gen(DS games). When the system was newer I had a higher limit, but not really anymore. I only buy games myself, I don't get games bought for me anymore.
The main reason people aren't willing to spend so much on games anymore is because there's a bigger selection available of used stuff. You can buy a full price current gen game, or you can buy older gen stuff for $5-$10 each. The games and systems that are available now used are still pretty good, there's plenty of people that would gladly play an NES, SNES, N64, Gamecube, Dreamcast, Genesis, PS1, PS2, Saturn, etc. The games are still pretty fun and plenty of younger people are looking for this stuff now. Back when the NES was new, what was the other stuff available? Atari 2600, Colecovision, Intellivision, etc. Those aren't that close to the NES, those other systems are still good but aren't anywhere near the same like the NES was.