"(Whereas repro cels, to refer back to the 
point of the thread, produce nothing.)"

I tend to disagree with that 100%

 They are promotional artwork and they can 
produce more interest and more customers for the 
anime studio production. They also can expand the 
fan base for the original product, just like 
Hankens can do (another form of advertisement). 

People may be interested in actually watching the 
anime, based off of the repros. hanging in some 
shop or on someones wall, cause they "look so 
good" and have "authentification" letters, etc.

That said, if there were a "hierarchy" set up, 
ranking production cels would rank about third 
for this type of collectible anyway,IMO. They 
would be behind original aritist sketches and 
hankens as far as "value" is concerned looking at 
the situation from the outside in. Of course, you 
may disagree.

In the future, as CG continues to replace hand-
painted work. Hand-painted repros, will in fact 
retain or exceed their current value, depending 
on the overall gross interest in the anime 
itself, IMO.

E.