Why do American textbooks often cost as little as half the price outside the US as they do at home? Publishers say prices are cheaper abroad because students in other countries can’t afford American prices. But some American students are catching on and buying their textbooks outside the US for deeply discounted prices. “To the despair of the textbook publishers who are still trying to block such sales, the reimporting of American texts from overseas has become far easier in recent years, thanks both to Internet sites that offer instant access to foreign book prices.”