CowBoom offers the used Sony PlayStation 4 500GB Console, model no. 10034PS, for $269.99. Coupon code "PS473015" cuts it to $219.99. With free shipping, that's tied with last month's mention as the lowest total price we've seen. (It's also $176 under the best price we could find for a new one.) It includes the system and power cord.
Note: No warranty information is provided, and this item may have minor scratches and/or be missing accessories.