Here we have two primary options for getting our hands on this book. You can rent it for for a few months for $18.90, or you can own it outright for $21.39. Two different service offerings: renting and retailing. Both result in the good, the book, being in your hands the very same day, through the same supply chain, therefore the experience will the same. The outcomes are different. One option will make you a renter, and the other an owner.
Which one should one opt for, well that depends on your outlook, and how you feel about the book before purchasing it. I believe Amazon will give you the option of owning the book for an additional payment. Or as it once happened with me for this book, when you don’t return the book on time, you default to becoming its owner. Amazon will charge you the difference.