I have been "in" to BMWs for a long time. Got my first one in '85 and haven't looked back. Even worked selling them for a time, and sold a lot of them. K1's were on the floor at the time.
Leftover K1's that is. They were a hard sell. No real luggage options - always a question from BMW riders. Also the bodywork, gauges, stickers... all ONLY for the K1.
By that time, the K1100RS was available. Faster, shared parts with the range. Not the K1. It's a rare bird all right, and god love ya' if you need to repair bodywork, luggage or gauge repair.
Rare? Yes. Desirable? To some. Will they ever be as desirable and worth a small fortune? Doubtful.
Ride 'em. Use 'em. Strip one and make a hooligan bike out of it. It's a motorcycle, after all