My guess is that the prices will not come down. 
Simply because Ghibli has not released the cels 
and most likely will not. The ones you are seeing 
somehow got into market through different 
channels (I'm no expert on this). So you won't 
all of a sudden see a bunch more cels and with 
the demand the way it is....

I suggest you save up if you want one. That's the 
only way ^^ Good luck!

Wendy