Newegg via eBay offers the Motorola Arris Surfboard 600 Series DOCSIS 3.0 Broadband Cable Modem, model no. SB6183, for $79.99 with free shipping. That's $10 under our Black Friday week mention and the best shipped price we've seen. (It's also a current low by $20.) It features download speeds of more than 600Mbps and upload speeds of more than 100Mbps.

Note that this modem may not be compatible with all service providers.