Allow me to add my voice to the others' here who
say that if you offer to pay the listing fees, the
seller might very well agree to relist the
auction.  I know I probably would, as a seller,
unless the bidder had excessive negative feedback
or didn't bother explaining why they wanted to
back out of the auction.

And now to commiserate with you, here's Yoko from
Bastard, who is less than pleased at the
whole situation.