CowBoom offers the used Microsoft Xbox 360 4GB Slim Console, model no. RKB-00001, for $59.99. Coupon code "GIFT2014" cuts the price to $54.99. With free shipping, that's tied with our October mention of a used model and the lowest total price we've seen. (It's a current low by $125 for a new model.) Features include 4GB internal memory and WiFi.
Note: No warranty information is available (a product protection plan is offered for additional cost). This used unit may be missing parts or accessories and have dents, scratches, or other cosmetic blemishes.