you can sometimes get good deals.. I just had a friend of mine here buy several moxes, 2 black lotuses (one NM and autographed, the other just good condition), time walk, time twister, ancestral recall, and some other high price cards.
total price for all of them.... 20$... this was about 2 weeks ago. He found them at a flea market.. Some guy sold his old cards and they were selling them all for that..
he took them to the local gaming store and sold most of them for a horrendous profit
I would have eaten one of the mox's just to spite a friend of mine.