I think the bigger problem is not the dep 
services, but the simple fact that each cel is 
unique. And cel animation is... dead? Which means 
that the number of cels shop owners can get and 
offer, is decreasing. Voilą. 
Once the studios picked the best ones for 
themselves, distributed some to shops, some to 
privates, and threw the remaining junk away... 
there're no more cels left. 
I guess the junk cels (like those I bought in 
Y500 bags of Shin Hakkenden containing random 
cels of about a 100 in number which sucked by 
99%) are what keeps dealers updating nowadays, 
because the better ones are often taken already. 

Sure, that sucks. But on the other hand, I think 
it's romantic to own the last ones of a dying 
species ;) (not that I support captivity of 
living beings though)

^^
Anna