NeweggFlash offers the refurbished ASUS Dual Band 802.11ac / 802.11n Wireless 1750 Gigabit Router, model no. RT-AC66R, for $89.99 with free shipping. That's tied with a deal from last month, which required a rebate, as the best price we've seen for a refurb. (It's $30 less than the best deal we could find for a new one.) It features a maximum speed of 1.75Gbps, dual-band support, four Gigabit Ethernet ports, and two USB ports. Deal ends January 28.
A 90-day warranty applies, but it's not clear who backs it.