This is probably old news for most, but I stumbled across this gold mine last night....
In Moonglade there's a town with a trader that sells the recipe for Runed Arcanite Rod, Felcloth Pants, and Superior Defense enchantment (all limited availability of course). I bought a copy of all three recipes for about a total of 5 gold and sold them on the AH between 15 and 20 gold (I was pretty damn happy this morning I must admit when I found out everything went for buyouts ranging from 5 gold to 10 gold).
The even better news is that the Horde has a flightpath in Moonglade that you can travel to quick and easy. I don't believe the Alliance has the same convenience (making the recipes perhaps attractive to sell in gadgetzan but I haven't tried AHing the products there). To get to moonglade is pretty extremely tough though - mostly 53's and 54's populate the trip through the cave to Moonglade. To get there, take the cave between Felwood and Winterspring and when you get to the bridge inside the cave, jump off the bridge and take the left (north) to Moonglade. The horde flight path is right to your immediate left after exiting the cave and the town with the Trade Supplies NPC is in the northwest portion of Moonglade (its pretty hard to miss).
Hope this helps someone. I just figured an approximate 10 gold profit could help anyone.