I was wondering the same thing, where are they 
getting the cels?  ^_^  And yes, the folks at 
concept do seem very friendly.
As far as "only 26 episodes, so not many cels" 
that's a load of bull.  FY OAV had fewer episodes 
than that, and there are still gobs of cels from 
it.  Even Ah my Goddess cels are not that rare, 
and it didn't have that many episodes either- the 
cels are pricey, but they are still around, even 
after the show has been out for ages and ages.
Devil Hunter Yohko had only 5 episodes, and it's 
pretty old, and cels from that show are still 
popping up.  Iczelion is a 2 part oav, runs less 
than 2 hours, and some of those cels still pop up 
here and there, and the prices aren't so 
outrageous.  So sorry, I don't buy the argument 
that a TV SERIES has so few cels.  That's 
something the dealers would like us to believe so 
that we will pay $300 - $400 for cels that will 
probably go for around $100 - $200 if they are 
released.