I essentially just ripped a guy off on my Alliance AH today. I got a Hyacinth Macaw for 3,000g.
On Horde side, it sells for ~20,000g.
In fact, a friend of mine begged a seller once to take a 25,000g Hyacinth Macaw down and let her save the cash to buy it off him. She couldn't because he'd already agreed to do that for someone else who wasn't going to be in game until the weekend but had the cash on hand.
And I have a macaw for both Bird and Dust, and all my friends have at least one by now, so I don't feel bad about using this one for profit.
:D Silly seller -- putting a bid-only price of 3k and thinking anyone on the poor half of the server would start a bidding war.