I have two great cel aucions running on eBay.  
The first is a great cel of a clueless C-ko 
being threatened by Mari from the original A-ko 
movie... very funny cel and hard to find!  The 
second is a cel of Wakaba grinning after Utena 
slaps her in episode 12.  One of the best shots 
I've seen of Wakaba.  Cels are listed at link 
above, as well as a number of manga, anime dvds, 
and soundtracks (all legit US releases)