if i'm understanding what you're asking 
correctly, then i'd have to say that that's never 
happened to me. all of the offers on cels that i 
have were from serious fans of those characters, 
so they were always willing to come through with 
payment for the cels.

however, if they couldn't come through with 
payment for the cels right away, then i wouldn't 
find a problem in that, either. i've held cels 
for people that have made me offers, too, until 
they were able to pay. and since i don't have 
such a relatively large collection of cels (even 
counting ones that i don't display, i'm sure i 
don't have as many as even half of the people on 
this board...), i've never found myself in the 
position that i needed money badly enough to sell 
them to someone else for a higher amount or 
because the person with dibs couldn't pay right 
away / at all.

haruna