My friends kids are both at university this fall and he was doing some ranting about the cost of textbooks. He is like many people. He just sends the kids off with a credit card to the campus book store and buys everything new. I know that is what I did my first year of university. In hindsight it was a terrible waste of money for me. There are a number of other options out there that you should never have to buy new expensive text books.
The first think I would do is look for used books. You can do this my looking for ads in your school newspaper. Students are always selling their books off from the pervious year. There are also flyers and bulletin boards scattered around the campus where you can probably find somebody selling their used books. We have a number of used books stores in town where you have a good chance at finding used text books.
If you can't find your text books used then I would shop around first before throwing out the money at the campus book store. They may not have the best price. There are a zillion online book stores. I would be willing to bet that you can find a good deal on those books.