On a hot summer’s afternoon at an outdoor flea-market, I ran across a cardboard box brimming with dust-covered cooking pamphlets. The dealer was preparing to leave when I started to rummage through the box. I asked for the price. With sweat dripping down his face, the proprietor replied a buck apiece. I slowly started to examine them. When almost everything else was packed away, the dealer proposed fifty bucks for the entire box. "What a deal," he proclaimed without exuberance. W...