College textbooks (search) are a lot fancier than they used to be. Some are complete with colorful supplements and computer software.

They're also a lot pricier, rising at more than twice the rate of inflation. A new report blames the price hike on those flashy new add-ons.

A Government Accountability Office (search) report finds the average student spends nearly $900 on textbooks and supplies.

At a typical public four-year college, that's 26 percent of annual tuition and fees. At two-year colleges — more likely to attract low-income students — the bill comes to 72 percent of tuition and fees.

Publishers say their new products aid learning and help overworked teachers. But critics say publishers are gouging students by "bundling" on unnecessary add-ons. They also accuse publishers of undermining the used textbook market by updating editions — even in subjects that change little, like Latin.