I've always used renfrew, the people behind the counter are good and are willing to go out of their way to ensure you get the right parts. They are willing to deal, just say "is that the best price you can give me?" but you usually won't have to do that. I was checking on header prices for the R/T and the first price they quoted me was employee pricing, no haggling or anything.
You start with a bag full of luck and an empty bag of experience. The trick is to fill the bag of experience before you empty the bag of luck.