I have an opportunity to purchase a 79 GS 850 GN for $2600. It is in mint condition, has good tires, good discs and runs fine. Is this a good price for a bike like this? I would also like to know about any potential maintenance headaches these bikes present. I am not new to motorcycling but returning after an absence of 12 yrs. My last bike was a Kawasaki 750 Specter and was a great bike. I would appreciate any input other owners of the GS850 could provide me with. Thanks!!!