I get that a MC dealer's cost on tires is a bit higher because thay have to hold a stock - and some will not be fast moving. Still, one of my local dealers got to know me and offered me a "deal" on a set of Tourances for my GS. They were going to order the tires for me so I eagerly waited while the parts guy figured the cost, including my big disount. It was going to work out somewhere upwards of $400, mounted. At that time, I could buy a pair of tires on the internet for $200 and get them mounted at an independent shop for $30. Needless to say, I turned down the offer. I liked the shop and would have been happy to let them make $50 off me - but $200+ - No F'ing Way!
I remember back in the late 80's driving my rusty old Triumph (car) to an Audi delaership looking at a late model Quattro turbo. The salesmen wouldn't even talk to me and weren't interested even when I said what I was looking for. Went back a few weeks later in the sports car I bought instead of the Audi. When they saw me pull up and look over a quattro, they were falling over themselves trying to get to me first. I got a test ride in the Sales Manager's personal demo. I and thrashed the hell out of that car for about thirty miles: Jumps, four wheel drifts and bouncing off the rev limiter, etc. When we pulled up back at the dealership, I told them that I didn't want it and why. The salesman who had been white-knuckled, digging his nails into the dash for the last twenty minutes or so was quite pragmatic, and said "Well I guess we asked for that one, didn't we!"