$20 · Powerline AV 500 Wireless N Extender

This requires an existing powerline adapter. With the PowerLine AV 500 Wireless Extender Kit, getting whole-home coverage is fast and easy. Simply connect the PowerLine adapter (that you already have) to your router's Ethernet port and plug it into a power outlet to turn every other outlet in your home into a possible network connection. Then plug the wireless extender into an outlet in a different part of your home to extend your Wi-Fi network to the hard-to-reach areas of your home like upstairs bedrooms, basements and outdoor patios.