That's a very fair price for a clean looking bike.
I picked up my 3rd K12RS/GT brick in August for just a bit less from a private seller.
Considering that your bike already had Speigler SS brake lines installed and has 9k miles less than the bike I found, you got a good deal. Enjoy!
98 K12RS taxi, 2000 K12RS taxi, 2004 K12GT, 2009 GSA, 2014 R-Nine-T