danno858 The seller paid around $13,000 for it when it was new. If I had$ 6,500 I'd probably by an acoustic piano.
I know nothing about this particular model, but usually people asking those prices have no idea. If you like the model and are interested, you can take two approaches to convince the seller. One is alone, the other is with the friend, basically doing the same thing.
Wait for a while from the original cg announce (not too little to let the person know that they have no other buyers, not too long since they may be in a hurry and since cg will delete the ad after about 45 day). Then contact and say: nobody cares about this instrument, look the new ones are so much better for these reasons, here is my best offer of x dollar, take it or bring the thing to the thrash which will cost you y so actually my offer is x+y.
Alternatively, do the same with a friend going first, making a even more ridiculously low offer, even something like: "it's so old and useless I'd just get it for free". If the seller takes that, good for you. Otherwise, proceed as in the previous case with a reasonable offer, which will sound a lot compared to the only other one (from your friend) they have received.
By the way, look at this! This is a great occasion for anybody interested: https://denver.craigslist.org/msg/d/firestone-yamaha-piano-nu1/7481068583.html (since the CG ad will disappear in the future, for the records: Yamaha NU1 in Colorado for $2300)