Although many stores offer free or $10 price shipping through Borderfree, the cost of returns is high and never told to you in advance, even if you ask. (the merchant will say that Borderfree sets the fees, and Borderfree is unreachable.)
I have been charged as much as $50 rerun fees for a $200 dress ordered from Piperlime.
This problem occurred for all the stores from which I ordered, which is a problem when ordering things that need to be tried on.