If the new edition is too different from the old one to make this a viable option, find out whether there's a paperback. The biochemistry tome's 2008 hardback edition sells for $193.63 at Amazon.com, but the soft cover version retails for less than $60.
No dice? Your next step would be to determine whether you intend to keep the book or sell it at the end of the semester. If you don't plan on saving your books, renting might be a good financial move.
A fledgling company called Chegg.com offers a vast selection of textbooks available for 125-day rental for about a quarter of the retail price. Chegg officials say they can ship books to you in less than three days, so delivery times shouldn't hamper anyone who thinks even slightly ahead. When you're done with the class, you send the book back, postage paid -- much like renting movies through Netflix.
The savings vary from book to book. "Exploring Psychology" costs $86 at Amazon but $28 to rent, while two popular biology books are about half the price to rent compared with buying, according to a listing of Chegg's most commonly rented texts.
When spot-checking Allen's list of "obscenely expensive" texts, I discovered that "Calculus: Early Transcendentals," by James Stewart, would cost $214 to buy but just under $60, including shipping, to rent.
There's no penalty for highlighting in the rented book (assuming you're not attempting to ruin it), said Jim Safka, Chegg's co-founder. In fact, "many students consider the highlighting a value added," he said.
"If a textbook is rendered unrentable, depending on where it is in its life cycle, we might charge the student for overuse," Safka said. "But 95 percent of our books come back just fine."
If you want to keep the book but can't afford the new-book price, you can always buy used.
In addition to the campus bookstore, there are at least half a dozen Web sites that sell used books in good condition, including Alibris, TextbooksRus, AbeBooks and Biblio. You can search each of these sites individually, or you can go to bigwords.com, which offers one-stop shopping.
In this case, the best price for a lightly used U.S. edition of this calculus book was $122. (An international edition was available for less, but the site warned that the numbers were metric and would not be comparable.)
The one option Allen warned students against buying was e-book versions of texts. A number of publishers offer online books for purchase, she noted, but they are actually one-year rentals. By and large, the e-books are available only through an Internet connection, and many restrict the number of pages you can print at one time.
Worse, you probably won't save enough on the e-book to make the inconvenience worthwhile. In this case, the calculus e-book cost $100 -- about $40 more than Chegg's rental and only about $20 less than buying a used hard copy. And, with the e-book, you don't have anything to resell.