Hi, Corgi Sakura.  The reason that you see so few 
Ein cels is that he is very popular among 
Japanese collectors (And I know of quite a few 
non-Japanese collectors who would love to get 
their hands on him as well.). Not to mention the 
fact that poor little Ein had the least screen 
time of the Bebop crew!

I have, however, seen a couple of Eins floating 
around Yahoo! Japan and eBay in the last couple 
of years. Animegame has one for sale right now 
(Ein w/Faye). Webdeb has a simliar shot, and I 
believe another collector once posted an awesome 
Ein w/the pet shop lady. I don't think it's in a 
gallery though. 

So, my advice is to stay alert and hang on to 
your pennies. Just like in "Stray Dog Strut," Ein 
is difficult to catch, but not impossible!

Good luck!

--Melissa