Lenovo offers Lenovo 510 Wireless Keyboard and Mouse Combo for $24.99 (reg $49.99) with free shipping.

Product Description:
The Lenovo 510 Wireless Combo Keyboard & Mouse is a keyboard & mouse combo that compliments your desk with a simple yet elegant design. Easily connects wirelessly with PCs using one Nano USB receiver. The keyboard is spill-resistant with island keys for typing accuracy and comfort. The accompanying wireless mouse has ambidextrous design and features 1200 DPI optical sensor. 

• Spill resistant keyboard
• 3-zone keyboard in compact form factor
• Island style keys for better accuracy and comfort
• Optical mouse with 1200 dpi resolution
• 1 nano USB receiver to control both keyboard and mouse
• Up to 12 months battery life (may vary based on usage)