Ring 10 piece Wireless Security System. $ 239.99 -$ 60 instant rebate.
$ 60 off valid until 1/5. (In store and online)
Includes:
(Keypad, Base Station, Range Extender, Motion Detector, and (6) Contact Sensors
Also on Costco.com:
4 pack of sensors: $ 69.99 S/H included