What we buy changes all the time, depending on our inventory on-hand and what is currently selling (or not selling). We will look at anything you want to offer, but there are a few guidelines that might be helpful.
We can't tell you over the phone (or by e-mail) if we would buy a particular book, unless it is very unusual. We never make offers over the phone; we have to have the book in front of us to establish condition and edition. We can't really say what we will buy at any given time, but there are certain things we do not buy.
Condition is very important to us and our customers. Though there are a few exceptions, we generally do not buy books that have been underlined or highlighted. We do buy certain library discards, but they must be marked as such. We do not buy books that are damaged, mouldy, or missing covers or spines.
We tend not to buy encyclopedias. We do buy some sets, but it is best to contact us ahead of time before lugging sets down to us. (You can always bring in a single volume from a set to give us an idea of what you are offering.)
We do not buy old editions of titles that are updated regularly, such as old textbooks, computer books, and travel guides.
We do buy textbooks, if current and being taken by our textbook partner. Because these aren't being sold in the store, condition and highlighting is less of a factor.
Having said all that, if you are not sure if we would be interested in some of the books you have, bring them anyway. Sometimes the most interesting books we see are the ones that people did not think were worth anything!
We pay based on a scale of what we hope to get for a book. While we make the highest cash offers around, we also have a liberal trade policy, with trade being good on all the used and remaindered books in our inventory as well as greeting cards. (Please note: trade issued at Moe's is not valid in More Moe's. The art shop buys for cash and trade also, but as a separate store.)