My buddies and I have long debated the worth of "fun". Definitely when assessing how much to invest in a video game versus the entertainment you get out of it is part of the equation. Of course, this is as fluid from one person to the next as any other preference.

Anyhoo, I've been playing a lot of Flyff lately, and it's free, but it has a 'cash shop' where you can buy items for your character. I decided this game deserved a bit of my cash, so I bought an in-game gift for my friend who introduced me. So I spent some money to support a game I enjoy, my friend got a free gift for getting me into the game, and I still paid far less on it than other games I play. Not too shabby.