**[1byone-US Store via ebay](http://www.passwird.com/links/eexiLC)** has a Infrared Driveway Wireless Motion Outdoor Alarm Sensor for **$9.99** with free shipping.

* Communication range of up to 100m/328ft
* [$19.99 at Amazon.com](http://www.passwird.com/links/PKxBwb)