I've seen a lot of 2010-2012 model 250 Pro XS and Sport XS "listed" for $8000 - $10000.
I have no idea what they actually sell for, it seems like it depends how bad someone needs one at the time it is listed.
I have a 2012 Sport XS SM 1:62s with a little over 200 hours, I'd love to sell it and buy a new 250R but I don't really feel like the hassle of listing it with so many on the used market for sale right now.