I went to Book Vault after searching on the web for "used" bookstores in the East Valley ... it's located in Power Square Mall in Mesa. It takes up 2 large shop spaces at the east entrance with other book tables in the hallway between the 2 shops ... one shop for fiction and another for non-fiction with the cashier in the fiction side. I asked and they said they have been open since 2010 and had collected books from many locations for several years before opening. They have a second smaller store near Lindsay & Broadway in Mesa. The store at southeast corner of Power & Baselie has many books used and new. Their trading policy is books accepted for trade given credit for 1/2 of the expected sale price. However, to use the trade credit you must only buy used books with it and you can only apply the credit to half of the used book price and pay cash for the other half. This is different than what I'm used to at Changing Hands books in Tempe where you can buy a whole used or new book simply using trade credit and no cash. Book Vault does have big selection of Biography and Fiction/Literature with books people are interested in buying and in good condition. However, the trade policy kept me from bringing my books in to trade, since I would still have to pay some cash in order to buy a book. If you don't mind that then this is a very good store to look for books. ... one thing they could do to make it more pleasant is to add music .. quiet instrumental music (no singers) would aid book browsing. As it is now, there is only a loud whoossshhh of industrial strength air conditioning vents overhead. Having background music would have kept me in there longer to browse. Also the woman, owner took personal calls and spoke loudly so you had to hear the entire lenghty call and she was not in a good mood. What happened to "lower your voice" when talking on the phone in public. She did answer questions when I asked and kept working shelving books, but she was not overly friendly or pleased that I had traveled all the way out to see her store for the first time. So it was just a "meh" so-so experience. And I didn't end up buying any books. It as just kind of blah.