You would enjoy REAMDE by Neal Stephenson. They build an in-game economy in an MMO based on physically modeling geologic gold production in the earth. The game-gold becomes a stronger currency than fiat, and people play the game as a way to earn money.
Discussion
awesome, will read
oshit
i remember the name but i don't remember reading it
snowcrash was so goood...
only author i remember reading about game economies might have been Cory Doctorow
which was it... little brother?