Some Target locations have the Roomba 650 model on clearance (MSRP $399) for only $188.
Brickseek link - http://brickseek.com/target-inven...72-07-0740
PS - I have this model and it has worked pretty well, but you do have to stay on top of maintenance like cleaning out the brushroll and filters frequently. If you want less maintenance, go with an 800+ model.
Currently $374 at Target.com and $299 on Amazon. https://www.target.com/p/irobot-1...nk=sametab
BONUS - SD user Coco_Chanel reported finding a Roomba 880 at Target for $151 when she went to find this deal - here's the Brickseek link - http://brickseek.com/target-inven...72-07-0505