What is the topic of this conversation?

M: Hey, Gloria. How would you like to increase the extent of your educational and historical background?
W: Steve, I don’t understand what you’re saying at all.
M: I just took my final in History 101 this morning, and I’m trying to get rid of the books. They cost $80.
W: Why don’t you try to sell them back to the bookstore?
M: I tried to, but they’d only refund $20, and I paid so much more for them. I’d like to get at least $40.
W: Well, I’m not going to lake History 101, so I’m not really interested in those books. Maybe you should ask some other friends.
M: I already have. Everyone I know has already taken History 101 and doesn’t want those books.
W: Why don’t you put up some advertisements in the history. building? Maybe someone you don’t know will call you and buy them.
M: I’ll try it, but I don’t think that’ll work.
W: Then you’ll have to go back to the bookstore. Twenty dollars is better than nothing.