At Plaza Books, our gently used books are priced at approximately half the original cover price. On paperbacks you can find that price on the first page; on hardcovers the price is affixed to the dustjacket on the back. (We cover hardbacks in mylar to protect the dustjacket.)
In addition to selling gently used books direct, Plaza Books also has a trading policy. When you bring books to the store for trade, we assign a value and give you store credit for them. In exchange, you can then buy our books at half our listed price up to the amount of credit accumulated. (Generally, that amounts to about one-fourth of the original sales price.) The other half is deducted from the credit.
The only books exempt from this policy are the antiquarian, collectible and hard-to-find books, usually marked with our code (NT) which stands for no trade.
No need to worry about bringing cards to get punched ... we keep your credit information for you and update it each visit.