All legit, no exploiting or chest/goblin farming at all. Pretty much attained from flipping on the GA till I accumulated some pretty good items. I have spent about 20 hours maximum flipping items on the auction house, and about 100 hours in game playing on my witch doctor, but that time doesnt matter since I haven't found a single good item worth selling.
So setting aside the hours I've played the game as just pure fun, that means I have actually "worked" 20 hours by flipping on the AH. That puts me at $50 per every hour that I have spent AH farming so far. It probably won't last very long at that rate but consider it a part time job that you had for a month. I'd say that it turned out to be VERY lucrative for me :)