Disklavier

I am new to this group and have posted only once before.  I am 
thrilled to say that I have found a used disklavier mx100II and will 
be receiving it in a few weeks.  My question is if anyone has 
knowledge of a second hand DSR1 (fat chance) or knows where a new one 
can be purchased for something reasonable?  $1,000-$1,300 is not 
reasonable. Are there other units similar to the DSR1 that can be 
used with the disklavier or is Yamaha and Yamaha only as far as this 
goes.

Thanks for your help.

Dave