Books are one of the trickier categories on Amazon because publisher pricing keeps most new titles from ever going on real sale. A new hardcover from a major publisher will sit at $18-22 and barely budge. Where the deals actually are: used copies from third-party sellers (a "very good" condition used book is usually indistinguishable from new), and Kindle editions, which frequently drop to $1.99-4.99 on backlist titles during Kindle deals events.

Kindle Unlimited is worth doing for one month if you read fast and want to binge a genre -- it\'s not worth the ongoing subscription unless you\'re putting away 4-5 books a month. Audible has a similar story: the credit model makes sense if you listen regularly, but if you only finish two books a year, just buy the individual titles. Amazon\'s own publishing imprints (Thomas and Mercer for thrillers, 47North for sci-fi) price their Kindle titles aggressively and often run free promos.

For textbooks, don\'t buy new from Amazon. Rent through Amazon\'s textbook rental program, check Chegg, or look for international editions -- same content, fraction of the price.