I recently checked up on the status of the iAuction plugin.
(seriously guys if you want a plugin, see if it exists or has been updated to work with the latest craftbukkit, anyone could have noticed that iAuction had been updated recently).
I won’t be installing it, because:
1) I like local shops. They give players something to build in their towns, and give people a reason to go to those towns. NPC shops are even better (once cough I make them work).
2) Spams chat. Mostly that’s fine, but the vast majority of auctions, people don’t care about.
3) Magic. It’s FAR too easy to transport tons and tons of stuff across the entire map. Your pockets are full of mountain, and you can just whiz it over to another person with a /auction command? It’s boring, it’s not “game”y. Some things SHOULD be hard. Even a little bit.