I would wait for another.  There is nothing worse
than spending all your money on a wishlist cel
just to have second thoughts about your decision.
 I did that on one cel because I was desparate on
finding one of the character and, let me tell ya,
it STILL bugs me to this day!

If it is just a line missing or something, that is
very easy to fix.  Just take it to a very good
artist who can fix that for you (real cheap and
easy).  If it is a paint chip, then it would
probably be more difficult to fix sincee the
person would have to go back and fit the proper
colors and then it may even be noticeable since
the original paint is several years old (not sure
about this).

I have attempted to go back and repair the cel I
have with paint loss, but the professional artists
were asking me between $100-250 to repair it.  So,
you also have to take the repair cost into
consideration when you buy it.  Best of luck to
ya!!  :)