xmartO via Amazon offers its XmartO 8-Channel 720p NVR Wireless Security Camera System with Four Cameras for $199.99. Coupon code "XMTPROMO" cuts that to $149.99. With free shipping, that's $250 off list and that's the lowest price we could find. It features Dream Liner WiFi relay tech that allows the cameras to work as wireless repeaters, an integrated router with 802.11n wireless, night vision, motion detection, and remote viewing via mobile devices.