Little Al,
As others have stated; I'd surely pin the dealer down as to the services performed and at what cost.
Good service departments will not only change the motor/transmission oil, and rear differential lube, but will perform a valve adjustment, not just listen to the valves - which is absolutely useless.
Another item, they should pull the rear wheel and hub, and lube the drive-shaft critical areas (as the above poster has suggested), plus the lube rear axle itself.
To answer the question regarding loss of warranty if the dealer doesn't service the machine.......baloney!
My Suzuki dealer has never serviced or adjusted the valves on My machine, however, they did replace My speedometer circuit board, and performed the recall service on the ignition switch wiring.....both warranty items.
I perform My own services, since I am qualified to do so, and if You are also qualified, save Yourself some dollars, and use the technical information on this site to assist with the job.