On textbooks

One thing I don't have to take with me to another country is textbooks in the sense of old ones that I used in school. But many of the books I own and will take are for teaching me things I need to know now. I think ordinary textbooks are good for certain subjects. But it does seem that many of them are overpriced. The publishers seemed to think they had a captive market who had to buy the books when assigned them for a class by a professor, but now I've heard that many now buy them used on eBay, which strikes me as a good idea. And the seller can raise a little extra cash for themselves too.