The textbook(s) for a course is chosen by the instructor teaching the course, unless there are multiple sections. In that case, a committee of full-time faculty members teaching the course makes textbook decisions. Regardless, the decision faculty have is a balancing act between selecting the "best" text for the class and the cost. Instructors have tried to control costs for students by selecting the paperback edition or the loose-leaf edition.
There are a number of options in purchasing a textbook. Often there are used copies, which are less expensive but are often dog-eared, previously highlighted, and missing ancillaries (accompanying CD's, etc), VS the prestine new copies shrunk-wrapped with all accompanying ancillaries.
The following was provided, in part, by an enterprising student in our Physiology class. The specific information will become outdated, but you will get the gist of the information.
In fall, 2008, Physiology 3 used Pearson's (publisher) Stanfield and Germann's Human Physiology textbook, 3rd ed. ISBN# 0805382860.
At the Pearon's website. List price is $165.33 (members pay $148.80)
At the SMC Bookstore: about $173.00 (new)
At the SMC Bookstore: about $130.00 (used)
At A&R Bookstore, the price is about $145.00
At Abe Books, copies started at a little over $70.00 (on a 24 Mar 2009 search). As always, the speed of delivery is a function of cost.
At Amazon.com, copies started at a little over $100. As always, the speed of delivery is a function of cost.
There is also the International Edition. The understanding is that it is identical to the state-side edition.
There is the paperback edition, and some textbooks are available in the looseleaf edition.
CAVEAT - you need to do your homework. Make sure you get the correct edition. There is a good reason why a $150 textbook is being sold for $10. Most textbooks come in various forms, e.g. with a lab manual, lab simulations, CD's, study guides, media updates, website access, etc. Know what the instructor is expecting you to have. Work with the ISBN number, and plan ahead as delivery often takes a week or more.