Disklavier

I have unsuccessfully attempted to sell my Disklavier recently via Ebay 
and a local Music web site.  Common issues seem to be the fear 
associated with the proliferation of Grey Market items and over 
inflated resale values claimed by Yamaha Dealers. i.e. My dealer told 
me mine was worth what I paid for it 3 years ago and so far that has 
been a joke.  In fact offers to date imply over a 30% decline in value.

So, I have 2 questions.  1. Does anyone know of a good/reputable avenue 
to sell my piano at a fair price?  (Other than my local dealer please)  
2.  Is there a book or web site that would give realistic resale values.

And I guess I'll ask a 3rd.  Anyone interested in purchasing a perfect 
DC2a Mark III?

Thanks for any feedback.