eBay seller japaneseculture is selling CCS cels 
(possibly the others too but I don't follow that 
series so I don't know) that are already listed 
on YJ at the moment.

I would think that maybe it was the same person 
and for some [accidental?] reason, they listed 
on both auction sites.. However, 
japaneseculture's cels come from DIFFERENT YJ 
sellers, not all the same YJ seller.

Examples (forgive me for posting auction links, 
however these aren't very desirable cels and I 
think it is worth it to avoid a possible scam):

Sakura cel:
http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&category=31374&item=3222635064

http://page5.auctions.yahoo.co.jp/jp/auction/e250
24862

Nakuru cel:
http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&category=31374&item=3222631012

http://page5.auctions.yahoo.co.jp/jp/auction/e162
33521


I've bought from one of these YJ sellers once so 
I just emailed them asking if they know what's 
going on.  I'll post the response if I receive 
one.

If anyone has any additional information or 
comments, please post.  :)  Thanks!

~Vamp