> Well, a small cel of an important scene is many 
> times seen as "better" than a great full face 
> shot of an unimportant scene.

Don't be silly : the back of a character is never 
going to have the same value as front close-up of 
the same character. Whatever the scene.

Sure, you may love a cel that is less good than 
another one for sentimental reason. But that's 
strictly personal. That's not what will define the 
value of the cel except to you and you only.

And now, if you say that a cel from an important 
scene is better than a similar cel from an 
unimportant scene, then you are just defining one 
of those objective criteria. Or didn't you noticed 
that usualy OP, catcheye, or other rarer scene are 
more expensive than common one ?!?