Tell you something else about Amazon. I ordered a book tonight. It had an Amazon price, and a certain number "New & Used from. . . . " I checked that option, and there were several sellers offering the book both new and used. One of them was Amazon itself, undercutting its own price by about 40%.
By the way, Amazon is getting bad about not shipping certain items to P.O. addresses. Ordinary, non liquid, non hazardous, conveniently sized stuff, and I don't mean their associated vendors; I mean Amazon itself. When they do that, I shop elsewhere.