Several third-party sellers via Amazon offer Prime members the used Cisco DPC3010 DOCSIS 3.0 Broadband Cable Modem, model no. AAC4002-10112234, for $21.95 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise shipping costs $10.95.) That's $8 under our mention from last fall of a used item and $7 under the lowest total price we could find for a refurbished unit. It features support for Gigabit Ethernet and USB.

Note: No warranty information is provided. Also, this modem may not be compatible with all service providers.