User blog comment:Aggression25/Why didn't Edward regain his left leg at the end of the manga/2009 anime?/@comment-1458758-20140914162009

The leg was the price he paid for his Mother's tansmutation.

The arm was the price he paid for getting Al's soul to bind to the armour.

Then Al reversed that trade, putting his Soul back beyond the gate in return for Ed's arm back.

Finally, Ed gave up his Alchemy to retrieve Al in whole.

There was no exchange that called for getting his leg back. Why he didn't ask for it into the bargain, who knows, but there you go. All the exchanges were deals with Truth. While the first deal cost Ed his leg, there was never a deal that returned it to him.

