How to make money in your MMO of choice; this is probably one of the most popular topics among players who want the best gear. Should you raid for rare boss drops? Should you buy low and sell high in the auction house? Should you farm for crafting supplies? Of course, each game's economy is different, but personal preference should dictate what you ultimately decide and how you wish to spend your time.
Over at Kill Ten Rats, they've written a great article on the phenomenon of item pricing in MMOs. The example is centered around the economy of Lord of the Rings Online and how you can allow certain people to inflate auction house prices beyond belief, to ultimately lower the item's price for others. It's an interesting take on an MMOs version of supply and demand, which isn't really even based on supply or demand, but the perceived version of either.