At least those people are getting something out of game. Completionists/collectors having their OCD taken advantage of are going to an even darker place.
Ah... I think you've given me the missing puzzle. I will say I don't get sucked into those "one up" wars (I really hate spending money on things I feel are gimmicks) _but_ this makes a lot more sense.
You aren't spending $25 on video game shit, you're spending $25 on a fun skin to show your pals, or upgrades to help your friends beat some boss, or whatever
Once you get on that path, it can lead pretty normal people to some very dark places indeed