Rhodes Chroma Polaris

>... do they go on ebay often ( how much ? ) or are they
> rare and unreliable?

I can certainly support the comments made by the others.  Aside from the 
membrane switch issues (caused by the internal connections), once a Polaris 
is working it tends to stay that way.

In terms of eBay availability and pricing, most times you can find one up 
for auction.  From my recollection, they seem to go for about $500US or so - 
although sometimes a bit higher (or lower).

If you can't find one on eBay, you might want to try some of the on-line
music stores (Daddy's, Rogue, etc.) - or you might have more luck with the 
"Ads" section of the Rhodes Chroma web site (which also hosts on 
Polaris-specifc files).

Check out:

http://www.rhodeschroma.com/?id=ads