Abt Electronics via Rakuten offers the Samsung POWERbot Cleaning Robot Vacuum
, model no. VR2AJ9020UG, for $399
with free shipping
. (Best Buy
offers it for a buck more.) That's $101 under our October mention and the lowest total price we've seen. (It's a current low by $10, although most merchants charge closer to $500.) It features a mapping system to navigate your home and rechargeable lithium-ion battery.