Patches and discussion for Ensoniq VFX family

I have a VFX-SD and SD-1 which I consider to be in excellent 
condition, given there age. I have had both of these units since they 
were new. They have always been part of a studio set-up and have never 
been on the road. The only trouble I have had with either is the plug 
problem on the VFX-SD which was fixed.

Can I get an opinion or two with regard to their possible worth on 
today's market.

Thanks