When people buy overpriced cels it hurts us all.   It
starts a cycle that rarely ends.  When cel owners
(whether is be US, Japanese or otherwise) see 
cels from a particular series going for higher prices
they start raising their prices (Assuming you are
buying from a primary source) which means prices
go up and up.

Below is a cel I paid about the same price for, actually
less, around $125.  All my UY cels have cost less
than $100, if your interested you can see them at
http://www.animanga.com/lemnear/Cel_Gallery/UY/uy.html
Even the Oyuki one only cost $70!