They have a very poor office supply format in their stores. Most Wal Marts have extra land that they could build add on stores. They can use their stock as their currency for the buyout and have a very low cash outlay. They would have purchasing power over the supply vendors.
Going private is not an option. No parts for an acquisitor to break up and sell off. There is virtually no players out there who need the real estate or the expense structure. Think bigger, Like Fedex Office or a foreign buyer like Tesco.