Many of the prices we pay seem to make little sense. We shell out $2.29 for coffee at Starbucks when a nearly identical brew can be had at the corner deli for less than a dollar. We may be less willing to give blood for $25 than to donate it for free. And we pay someone to cart away trash that would be a valuable commodity in poorer parts of the world.

The Price of Everything starts with a simple premise: there is a price behind each choice, whether we're deciding...