9to5Mac reviewed several iPad Air keyboard cases and found the Logitech FabricSkin to be the winner:
Using the accessory as a case for the Air while not in keyboard mode is comfortable and convenient. Relatively, the cover (which protects the front and back of the iPad Air) is not much bulkier than a non-keybaord case built for the same purpose. However, the electronics in the accessory add some weight. The volume rocker, rear camera, speakers, and power button are all accessible while the cover is closed.
Best Buy has the Belkin – QODE Ultimate Keyboard Case for Apple iPad Air – White Model: F5L151TTWHT for $39.99 with free site to store. That’s easily the lowest price we’ve seen.