We run a 4240 tractor and a 1600A haybine.  We mostly deal with Agland Vermilion for parts and Agland Lloydminster for toys.  It is a BEAUTIFUL store, but it confirms my belief that they must charge too much.  Their parts are very reasonable and the parts guys are very, very good in Vermilion.  We have found it is usually cheaper to buy genuine than to buy aftermarket, but if no one else makes it, then they certainly charge at will.