gotta agree with everyone else :P
gravi cels are tough to find but once in a blue 
moon, yahoo japan will have one or two...
in fact bout a week ago there was this sweet 
shuichi pan cel... lost it of course *gaaah* 
(still just a widdle bitty bit bitter about 
it)... 
anyway back to the point, there are some amazing~ 
cels floating out there but they can get darn 
expensive and yahooj is the best bet on finding 
them cause i think a lot of times private gravi 
collectors would rather starve than give up their 
beloved gravi cels...at least that's how i feel 
about mine ^_^

~ryoendymion