IF you want to avoid any conflict with the stupid
kid (was going to substitute it was another phrase
inapropriate for this forum), then you can refund
their money MINUS all expenses, Paypal, Ebay, etc,
etc.

I did see your auction and it definitely said "fan
cel" in the title.  So . . . even if the kid does
throw a fit and tries to contact Ebay, Ebay would
do absolutely NOTHING about buyer's remorse.  The
only issue you can have is the feedback issue.  If
you don't care about that, then it is settled. 
But, be sure to send them the package and put full
tracking on it.  Otherwise, they can claim that
you didn't send it and try to get their money back
through Paypal, etc.

Best of luck!  I know it is tough dealing with
many people, especially those on Ebay during this
time of year who have absolutely NO IDEA
whatsoever on what they are doing or even what
they want!  Grrrrr . . .
I work for a toy store.
toys + christmas = HELL!!