“...it is when I'm buying books that I encounter the greediest people: the person selling his collection who will push to extract every last penny that they're worth from the bookseller they're selling them to, will inevitably be the same customer who will drive the price down to the very margin when he's buying books. And while this is arguably good business sense, it has rather an unsavory whiff about it. There's no sense of fairness. Conversely, the customer who brings in books to sell and is happy with whatever you offer him will be the one who doesn't attempt to push the price down when he's buying books from you.”