iRobot Roomba 870 Vacuum Cleaning Robot for $414.00 shipped. Here is a screenshot for reference. Alternatively, it is available at Amazon for $419.00 shipped. Its iAdapt Navigation uses a full suite of sensors to navigate and adapt to a changing home. It also features tangle-free extractors help prevent hair and debris clogs. Most places have it for about $549.
This post has been revised.