tekdeals via eBay offers the refurbished Apple Wireless Bluetooth Keyboard, model no. MC184LL/B, for $29.99 with free shipping. That's tied with our mention from July and the lowest total price we could find now by $6. It features an intelligent power-management system to conserve battery life, aluminum casing, and 30-foot range. It requires two AA batteries.
Note that a warranty is included, but further details are unclear.