I've had 6 legendaries, and a set item drop in maybe 170 hours played. I've never had more than 210% MF (counting 5 stacks and maybe a buff).
My farming set has roughly 115-120 MF (goes up or down a tad sometimes when I replace an item).
Now, that may seem lucky, but here's the thing: of those 7 pieces, only ONE was even remotely good enough to sell. The rest were so god awful, I couldn't pay someone to take it. At least the ring sold for a bundle.