It seems like you pay up front with cash and video making before and after new parts, then you get discounts from a few parts companies. The companies write off the discount as advertising, and the middleman keeps the first payment for their time and overhead.
I would prefer to have more of a choice for where I buy parts, but this could save you money in the long run if you buy a lot of parts from the companies listed and they keep giving you a discounted price.
“Do…not waste time protesting the self-inflated showmen and bloviating bullshitters who populate our culture. It’s more fun to marvel at them, to appreciate them, to be grateful for them, and to mock them relentlessly. ”-from the 2010 book American Freak Show by Willie Geist. "He wondered what difference any of it would make two hundred years from now." -from the book Cyclops by Clive Cussler.