Buy.com has D-Link ANT24-0700 2.4GHz Omni-Directional 7dBi Indoor Antenna for $9.99 + free shipping.
D-Link introduces the Omni-Directional 7dBi Indoor Antenna (ANT24-0700) designed to provide extended coverage for an existing 802.11b/g wireless network. The omni-directional design of the ANT24-0700 offers dramatically increased wireless signal coverage in all directions. With 360° of better signal reception, this high-gain antenna will also improve data throughput at farther distances.
The D-Link ANT24-0700 connects to a variety of wireless routers and access points on the market today. Whether the wireless router or access point has an SMA or TNC connector, the ANT24-0700 comes with an RP-SMA to RP-TNC conversion adapter to accommodate either connector type.
For maximum placement flexibility, the ANT24-0700 comes with a magnetic base unit* with 1.5m extension cable and a mounting kit. The magnetic base unit has an incredible strong hold onto any metal surface. Avoid the cost and complexity of adding additional access points or repeaters when you can easily use the ANT24-0700 to help improve wireless performance. Enjoy the benefits of wireless connectivity at greater distances throughout your home or small office.
D-Link ANT24-0700 2.4GHz Omni-Directional 7dBi Indoor Antenna $9.99 FS 
