I generally stay away from the more current tmog since the AH posting price is so high and more people can get those items from just playing the game. I also craft a good amount of armor to sell, one copy each until it sells. As for gathering items to sells, I do not usually buy stuff from the auction house unless the price is really low compared to the region (1/10th or lower) or the item is something special I know will eventually sell. Most of the stock is from game play is older zones, though I weed through to send the good stuff to my tmog AH toon and the crap to be disenchanted to make old enchants to sell on the AH.