Half-Price Books is a wonderful little bookstore in this large shopping area in Mesa. It's right near good places like Best Buy and Fuddrucker's. I have found that Half-Price is my favorite used bookstore when I've got certain titles in mind. Their selection is quite large for the space it occupies and their sale areas are a great place to find books.
I've done a few trade-ins at Half-Price, and found them to be pretty stingy with the amount you get for your books. I like to take items to Bookman's first. Bookman's won't take everything but they will give a fair price. Whatever is left, I take to Half-Price, because they will take the entire box, but they don't pay much.
They have a calendar every year, which you can get free during the beginning of the year with (I believe) a $30 purchase. The calendar comes with coupons spread out over the remainder of the year. They also have a teacher's discount, which my husband was able to get. They occasionally say this discount includes libraries, but when I asked the staff member said that inclusion had been discontinued. Oh well - my husband's discount is very nice, anyway.