I've seen a fair amount of "close up on one or 
two eyes" or "just a hand" (though often holding 
an important object in the series or doing 
something special) cels floating around.  If you 
look around a few galleries you might find some 
(Fushigi Yuugi comes to mind for eye closeups but 
I can think of singletons from other series).  I 
think they generally go for less than the 
standard portrait but I've seen a few hand or eye 
cels go for not exactly cheap ^^;

I too am looking for a couple special hand or eye 
cels.  I'm just waiting for them to pop up some 
day.

Keys