To me, backlit cels are a pain in the butt since 
I'm eternally short of cel bags - and backlit 
cels *MUST* be in a cel bag or they stick to 
absolutely everything. Another problem backlit 
cels can have is that the paint can crack more 
easily. (Seems that heavy black stuff isn't as 
flexible as the normal paint.)

I don't know that they're worth more - if I were 
to sell one, I would note it as such. . . But 
really only as an informational fact. It is true 
that when a cel is backlit, you often can't see 
many of it's details on the screen while watching 
the anime. . . Only by having the cel in front of 
you do you get to see details that are washed out 
by the backlighting during production.

Like with anything in collecting, the only thing 
that matters is if the owner cares.

Many Sharp Smiles,
--Drac