Amazon offers the iRobot Roomba 780 Vacuum Cleaning Robot for Pets and Allergies, model no. 78002, for $599.99. In-cart, that drops to $399.99. With free shipping, that's tied with our expired mention from two days ago as the lowest total price we've seen for this model. (It's also a current low by $187.) It features dual HEPA filters, infrared remote, and up to seven scheduled cleaning sessions per week.