was farming MC, AQ, ZG and BWL (bwl only a few times, just for the ores) for 3-4 months with a friend of mine..we completed mats for 2 thunderfuries (got one, my m8 needs 1 binding), we made a sulfuron hammer and i have banker with items worth 12800g... just think how much more we got from bosses and trash/junk There was a time i had 13k gold and I never done any dailies or farming whatsoever, just raiding, pvping and old content clearing..
so yes, very profitable, especially if u have multiple alts and a few hours to spend per week..