As one of its daily deals, CowBoom offers the used Xbox One 500GB Console, model no. 5C5-00001, for $209.99. Coupon code "YESPLEASE2015" drops it to $167.99. With free shipping, that's $37 under our mention of a used unit from three weeks ago and the best price we've seen. (It's also $163 less than the best price we could find for a new unit.) Deal ends today.
Note: No warranty information is provided. This item may have scuffs, blemishes, and scratches and does not include the controller, HDMI cable, or owner's manuals.