What are the two speakers mainly discussing? What does the clerk imply about the previous book return policy?

Listening to part of a conversation between a student and a bookstore clerk. (S = Student, C = Clerk)
S: Hi, I’m here to return a book that I bought for a psychology class. I dropped the class, so… I won’t need the book anymore.
C: Well, have you checked our return policy?
S: No, why?
C: Well, you should have done that first, it’s printed on the back of your purchase receipt and it’s also posted at the front of the store.
S: Okay, here’s my purchase receipt… urn… but why do you ask?
C: The school does allow students to return books, but only one week after the start of classes, and, well, I’m sorry, but you bought this book two weeks ago.
S: Ugh, I’ve been so busy, that’s why I dropped the course in the first place. I mean, look at it, it’s completely new. I didn’t even write my name on it.
C: Yes, it does look like in very good condition, but I’m really sorry. That’s the school policy.
S: The school should really change the policy. One week isn’t really a whole lot of time. I mean, it shou until the middle of the semester or something, you know?
C: Yes, well, the school changed the policy about 7-8 years ago. The school used to allow returns during the entire semester. But what happened was that after students took a class, they would bring back their textbooks to the bookstore and ask for a full refund for the book at the end of the semester.
S: Oh, no! Then there’s nothing I can do.
C: Well, the school does buy books at the buyback price. But, it won’t be a full refund.
S: Okay, so how much is the buyback price?
C: Oh, it’s 50% of the original price of the book, and only if the book will be used by the school for that class during the next semester. Let me check, what was your class number?
S: Psychology 201.
C: Okay. Hold on just a second please while I look that up. Well, it looks like the Psychology department is planning to change the book next semester, so they won’t be using the book you have. Em, that means we won’t be able to buy back your book.
S: What? Then what on earth am I supposed to do now?
C: Well, we have an agreement with the book distributors. They buy back any books that we can’t sell, and then they sell them to other colleges that still use the books as used books. But, their buyback price is pretty low. Your book will probably come out to about 25 dollars.
S: Jeez, are you serious? I paid over a hundred bucks for this book and I mean I never used it.
C: I know, I know. Well, however, this is sure better than before when we didn’t have any agreements with the distributors.
S: Really?
C: Yeah, back then, we couldn’t do anything for the students. They couldn’t return any books even if they dropped a course within a week. So, I’m really sorry, but, at least you can get some of your money back.
S: Yeah, I guess so. I’ll do that then. Anyway, thanks.