That leads to a big frustration for used-book buyers: page numbers and test questions can change, which can cause confusion if the professor makes assignments using only the newest version. (If the professor happened to write the textbook and requires the newest edition, he or she is likely to earn a lot of students' resentment.)

Another frustration: professors who don't post their syllabuses until the last minute, forcing their students to scramble to find used and rentable copies. Sometimes, these copies take several days to arrive, meaning the students start the semester already behind on their work.

The gradual shift toward digital or e-textbooks that's already under way could help bring costs down by eliminating printing costs -- although publishers will still face the remaining, typically more expensive upfront costs of having to pay writers, editors, designers, artists, the marketing staff and so on.

Of course, there are downsides to digital textbooks as well. They're often sold with an access code that expires or that can't be transferred or sold. If e-books did replace traditional books, the used-book market could shrink dramatically, and students might be back in the situation I faced in college, with few options beyond those allowed by big publishers.

Then again, one of the things slowing the adoption of e-textbooks is the students themselves, who prefer printed material, the Student PIRGs' Allen said.

"It's what they grew up with," Allen said. "It's what they're used to."

Still, the Student PIRGs champion the free open-source textbook, like those provided by one of the Textbook Rebellion's sponsors, Flat World Knowledge. Flat World provides students with free online textbooks that professors can readily modify to fit their courses. Flat World Knowledge makes its money by providing study aids and alternate forms of the books (print, audio and .pdf files, for example).

But the company has only a few dozen titles, compared with the 350,000 textbook titles currently in print that are available from traditional publishers, said Bruce Hildebrand, the executive director for higher education at the Association of American Publishers.

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So again: There are no easy solutions. But a hat tip to the Student PIRGs and the Textbook Rebellion for keeping attention on this issue. Open-source materials won't be the solution for every course, but professors and universities need to be reminded that they -- and not just their students -- should be looking for alternatives to the $200 textbook.

Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.