Watched a bunch of the Mecum Motorcycle Auction from Las Vegas. Some of the sales I noted:
1987 K75S, 64,770 miles, good used condition. Red paint with no readily visible rash. Sargent seat, Parabellum screen. Crash bars, aftermarket shock(Progressive?). Lots of "patina" on exhaust headers. $2200
https://www.mecum.com/lots/LV0122-488850/1987-bmw-k75s/1991 K1, 18,559 miles, almost showroom condition. Black with the discrete graphics. Stock with no visible modifications. $7700
https://www.mecum.com/lots/LV0122-489213/1991-bmw-k1000/1989 K100RS SE, 23,448 miles, excellent used condition. Blue grips, and Bungie Buddies on white side cases, otherwise looks stock. Paint in excellent condition, some "patina" on the headers, and some very light wear on footpeg plates. $6600
https://www.mecum.com/lots/LV0122-489212/1989-bmw-k1000rss-special-edition/1989 K75RT, 242,951 miles, non-running. Blue with lots of "patina", battery cover missing, crash bars, gaiters, LT "gauge console" above instrument cluster. $110
https://www.mecum.com/lots/LV0122-488729/1989-bmw-k75/There were a number of R bikes that seemed to go for about what they list on Craig's List for. Lots of very nice antique machines going back as far as 1902. Honda CBX's going for $20K+ and Kawasaki 500 triples in high teens. Strange, there were a handful of choppers that got nice money, but not one cafe custom.