Amazon offers the refurbished Netgear Arlo Pro Security System with Five Cameras for $569.99 with free shipping. That's $4 under our Cyber Monday mention of a new unit and $170 less than you'd pay for a new system elsewhere. (However, most sellers charge $807 or more for a new system.)

The system includes five cameras and a base station. Each weatherproof wireless camera features a 1280x720 (720p) video resolution, 130° wide-angle lens, night vision up to 25 feet, motion detection, 2-way audio, rechargeable battery, and magnetic mount. The base station features a 100-decibel siren, support for live monitoring, 802.11n wireless, and USB.

Note: A 90-day warranty applies, but it's unclear who covers it.