Some of the most advanced Roomba robot vacuums are on sale right now. Wellbots has the poop-detecting iRobot Roomba j7+ for an all-time low price of $549. Or, you can opt for our favorite vacuum / mop hybrid, the upgraded j7+ Combo, for $799. In both cases, you can enter the coupon code ENGROOMBA200 to receive the $200 discount exclusively for Engadget readers.