Me and my friend were messing around with people on AH with a Large Prismatic Shard, putting it on a 1 copper bid and watching the bid go up. It got boring so i figured while the bids sky rocketed i would throw up a 1000g bid and see if someone would out bid me. Turns out they did. 1050g bid on 1 LPS. So funny watching people make fun of this guy in trade chat.
Anyways this is real easy to do.
1. All you have to do is put up a valuable item on AH and put the bid at 1 copper.
2. Advertise your item in Trade channel for 1 copper
3. People will start to bid like crazy
4. Have your friend throw up a high price bid and watch someone accidentally outbid you.
5. GG you win a lot of money
Note: if someone doesn't outbid your friend you can always take the item off the AH and try again.