Yeah...of course, a low flow of D cels into the 
market can also make for the high prices ^^ Right 
now people are willing to pay a LOT for a nice 
image of D.

As for popular scenes/characters...

D, most definitely. Most likely with his fangs 
bared will be more prized...

Carmilla, no doubt about it. Not only does she 
have an AWESOME character design, but she has 
very little screen time, all things considered.

Then (SPOILER!!) ...D's mother. ONE scene in the 
entire movie...whew, can't wait to see the rush 
on THAT one. (END SPOILER!)

And (SPOILER AGAIN!) young Leila (poofy pigtails, 
kawaii!). (END SPOILER!)

-Misha