I think I know what dealer chipn is speaking 
of. :) I end up buying at least one cel from him 
at every Otakon... but always the cheapies. At my 
first Otakon I found a cel of Mosquiton from 
Master of Mosquiton in his 1920's bathing suit at 
his table at a price in the two-digit teens, and 
last year a really cute Nuku Nuku OVA cel. 

I always hit the cel tables first, because if you 
want to get the good stuff you have to get there 
early. Of course, if I went to one of the cons 
earlier in the year the selection would probably 
be even better... but c'est la vie. :)