“The not very glamorous economic answer is that it’s a lot easier to make money selling used books. … On the whole, the problem with new books is that there’s a list price set by the publisher and a discount price that’s also set by the publisher. So, as a new bookseller, you have no control over what the book sells for or what you pay for it. With used books, if you’re smart, you find ways to get them cheap, and you decide what you price them at.”