Today only, Samsung offers its Samsung POWERbot Essential Cleaning Robot Vacuum in Graphite Silver, model no. VR2AJ9020UG, for $399.99 with free shipping. That's tied with last month's mention as only a buck more than the lowest total price we've seen. (It's the best deal today by $150.) It features a 10-sensor mapping system to navigate your home, CycloneForce design, 0.7-liter dustbin capacity, 12.2" cleaning path, motorized brush, EasyPass wheels, remote control, and rechargeable Li-ion battery.