Few things...have to know your dealer, is he a big, high volume dealer use to moving iron or a small "every sale counts" type of guy....usually, the bigger dealers will come off the price a little more....
this is one of those rumor/consumer logic untruths that just won't die.. haha.
no offense I deal with that crap all the time. I work at a smaller chevrolet dealership and we are surrounded by large dealerships... if what your saying is true us,, as well as every other small dealership in the world would have gone the way of the dodo long ago. .
in reality it doesn't matter about the size... we're not talking about buying in bulk here.. it's a bike/car everybody pays the exact same thing to buy them from their respective manufactures...
in all honesty it's actually easier to get a better deal from a smaller dealership.. especially if you do a little shopping before you go...
Another thing about smaller dealerships is you get treated better (this is almost universally true in my opinion) more people at a small dealership will know you and most of the time they are very interested in having you as a returning customer as opposed to the big guys.
I'm babbling here... but I know the dealership i work at would much rather make a very small sell just to have the chance to show you how much better their customer service is knowing that the next time you buy you'll know it's worth a few extra bucks to stay with them and the excellent service...
as opposed to large dealerships that want to make as much as they can and then let the service department worry about providing you service... and if you come back.. thats great.. but really.. do you remember your salesmans name from the last time you bought a car/bike?