Walmart offers the factory-refurbished Motorola Surfboard DOCSIS 3.0 Cable Modem, model no. SB6121, for $44.78 with free shipping. That's tied with our mention of a refurb from two weeks ago as the lowest total price we've seen. (It's also $24 under the best price we could find for a new unit.) It features support for IPv4 and IPv6 and enhanced network management. A 1-year Motorola warranty applies.