As one of its daily deals, A4C offers the Nest Secure Alarm System Starter Pack for $249 with free shipping. That's tied with our mention from two weeks ago as the lowest price we've ever seen. (It's a current low by $51.) Deal ends today. Features include:

Nest Guard base station with 85dB siren and motion detection up to 10 feet

2 Nest Detect door/window sensors with motion detection up to 15 feet

2 Nest Tags (with support for up to 10)

802.11n wireless & Bluetooth 4.0

remote access and security alerts via Nest mobile app