I am not sure if any one has posted this i didn't see anyone who had but I have made a profit doing this fairly easily it is more for the casual acctioneer types:
Get Acctioneer!!! (or some other comparable mod)
Become Notorious on your server talk in trade and do things that get you noticed.
Search the AH for items where the bid is low but the by out is high, or has no by out, and people are bidding agianst you in a war then PM the person who is posting the item and tell them they made a mistake and offer them a lower price than the worth but higher than the current bid and convince them that they won't make a profit unless they sell to you :P
Resell your loots lol. I can't count the number of people i have swiped shit from this way it makes me lol.
Hope that helped.