Some options for purchasing the book:

   1. On paper (e.g. from Campus bookstore: $84 new, $63 used; Amazon.com: currently unavailable as this is written)
   2. Electronically, either from
       a. CourseSmart ($40.50) http://www.coursesmart.com/047146886X
       b. Wiley E-book (via VitalSource) ($48.50) http://www.wiley.com/WileyCDA/WileyTitle/productCd-0470230134.html

Some students may prefer to have the paper copy of the book to hold in hand, flip pages, etc. Some may prefer not have to carry the book around, and/or would like to save some money. (But note you can sell the textbook back to the bookstore if you wish.) The electronic versions have nice reading applications, with good display options, and the ability to search the text, and to insert highlights and notes in your copy. It seems most suitable if you have a notebook computer. CourseSmart is a little less expensive, and has the advantage that you can choose either an online version or a downloaded version of the book. However it has the disadvantage that you don't keep the book: it expires after 180 days. Once you buy the book from Wiley (or VitalSource), it's yours to keep. Also, that lets you download the book to two computers rather than just one.