Newegg offers the refurbished Asus Dual Band 802.11ac Wireless 1750 Gigabit Router, model no. RT-AC66R, for $89.99 with free shipping. That's tied with our mention of a refurb from a month ago and the lowest total price we've seen. (It's also $65 under the best deal we could find for a new unit.) It features a maximum speed of 1.75Gbps, dual-band support, four Gigabit Ethernet ports, and two USB ports. Deal ends April 29.
Note: A 90-day warranty applies, but it's unclear who backs it.