I assume you went to the bookstore? Bad idea, man. Going to the bookstore is like walking into Harlem with two grand in cash and looking for hookers. You're gonna get ripped off. And I don't mean ripped off as in "Oh shit, I got a bad deal". I mean ripped off as in "Oh shit, someone clubbed me in the back of the skull with a tire iron, stripped me of my anal virginity and took all of my cash and credit cards".
Here's my advice. Return your books immediately. Search for them on Amazon, and for each one click on the "Buy New and Used from $..." button. My books were $410 at the bookstore (almost entirely Used too), they were $180 online.