I have some friends and guildies that also work the AH. We focus on different markets and work the AH at different times. I have one set up to snatch a few items for me because he is on a totally different schedule than I am. He just sends it COD to me at a set price.
Any time that item dips lower than my price he will make a profit on selling it to me. These are items that I buy like mad so having a 2nd person buying for me can only help. It also keeps it out of everyone elses hands.