A guy in my guild has made 3.3 million in three weeks, so it's definitely doable. He's doing something called 4x2, where you get 2 groups of 4 people as then everyone can loot the same mob (any more or any variation other than 4x2 and it tags the mob grey). Between the drops (including a couple of mounts) and just vendor crap, he's made loads. He's also running all the old raids across multiple difficulties and that makes quite a bit of money (especially wod where you can do them on all difficulties).
Also, when did you level a mage? I ain't seen you on!