Cels from Shamanic Princess have gotten a little 
more rare in the past year or so.  But so have 
cels from most series a few years old =/.  As 
for a transformed Tiara cel, I am not sure quite 
sure which version of her you are asking about 
in particular.  The cels of her normal 
transformation, with red wings and such run in 
the price range of about $100 to $500.  Possibly 
more is depending on the pose and expression.  
Or if the transformation you are looking for is 
the brief transformation where she has one white 
wing, and one dark, then I would have to say 
your price range is about correct.  The problem 
is, there are virtually none of those cels out 
there.  I was extremely lucky to get mine.  But 
in two years, I have not seen another one for 
sale, so it is hard to gauge the current price.

From the way I am reading your message, I am 
assuming you are asking about a cel, a dealer 
has in their collection.  If you are just making 
an inquiry about selling a particular cel, you 
really have little to lose.  Most dealers I am 
sure are use to such things, and have responded 
to similar request I have asked. Just be polite, 
and I am sure you will get a response. Whether 
or not they decide to sell to you or not, is 
entirely up to them. But at least you will know. 

If you are asking a dealer to look for a 
particular cel for you, well in my experience, 
this does not really happen. As they have told 
me in the past, they receive numerous requests 
to find particular cels, and it is just too hard 
to keep track of them all.  But then again, 
there is little harm in asking.

Fenris