Why are college textbooks so expensive - Business Insider

"Textbook costs overall have risen 67% from 2008 to 2018 — some four year college students spend close to $500 a year on textbooks.

Almost 80% of the textbook industry is dominated by five publishing companies — Pearson Education, Scholastic, McGraw-Hill Education, Cengage Learning, Houghton Mifflin Harcourt. 

These companies do everything they can to keep their books expensive and prevent students from renting older versions.  ..."