RadioShack offers the Motorola SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem, model no. SB6121, for $69.99 with free shipping. That's $5 under our mention from two weeks ago and the lowest total price we could find by $10. Sales tax is added where applicable. The SB6121 features upstream and downstream channels, support for IPv4 and IPv6, enhanced network management, and more. This modem may not be compatible with all service providers.