Slogan for used book store?

I'm opening a used bookstore next month.Name is The Book Exchange.I will be selling and trading books.Books brought in will be given a resale value and customers who brought in the books will be given store credit.When they wish to purchase books,they may use credit for half the total purchase and pay cash for the other half.Those who did not bring in trade books pay full price for their purchases.Anyway, I'm trying to think of a catchy slogan.The store is located in a building that also has a martial arts academy.For our newspaper ad,I've already thought of "Come in and excercise your mind AND your body!"However, I'd like other ideas.