MacMall offers the Kensington KeyCover Hard Shell Bluetooth Keyboard for iPad, model no. K39785US, for $14.99 plus around $6 for shipping. That's the lowest total price we could find by $4. It's compatible with 2nd-, 3rd-, and 4th-generation iPads and features an adjustable stand and auto sleep.
From shoes to cookware, if you're willing to pay a little more for these awesome products, you may never have to shop for another again.