Why do I have to do the work for them and tell them what the part is worth?  If I am supposed to be loyally supporting them, why aren't they loyally looking out for me by providing parts at the best price availible?  The business of calling them and telling them they need to have a better price implies that either a) I am a better parts man they they have, because I can find better sources then they can, or b) they care only about how much they can screw me for and are going to overcharge every chance they get and see if anyone complains.    If the answer is a, then they deserve to go out of business because they apparently suck at their job.  If it is b, then they deserve to go out of business because of the way they treat their customers.  Either way I refuse to accept any responsibility for the poor service they provide and whatever negative result it may produce for them. 

Still goes back to the concept of supporting the most local business I work with.....my own.