Why do they charge so much for college books?

It seems like a conspiracy. I am taking two classes this summer and my books were over $200!!Why do they charge so much for college books?
It is a conspiracy. What drives me crazy is when they come out with new versions and all they change is a few of the questions and add a few paragraphs. But then you can't use the old version or you get random wrong answers.



I have read that the printing companies sometimes give kick backs to colleges to encourage them to order the most recent version, even when there isn't significant changes in the technology. For example...18th century American literature hasn't changed much since the 18th century. Do we really need new versions every year?Why do they charge so much for college books?
It takes a lot of research and effort to write books with that much mis-information in them... and that costs' money to produce.Why do they charge so much for college books?
It's not just college books but all books. I work at a high school %26amp; can't believe what we have to pay for some books!!! It's crazy!