I'm currently selling a Microsoft Wireless Optical Desktop Elite Keyboard and Mouse. The starting price is way under the retail, starting at $19.99.
The item is in brand new, out of the box condition. I tested it on my system, and everything worked great. Everything is included: Keyboard, Mouse, Receiver, and the Installation Disk. Easily installed in under 5 minutes!
As a bonus, I have included all 5 alkaline batteries I used to test the setup. All brand new. You'll be able to power everything up the second you receive it.