Newegg offers the refurbished Asus Dual-Band 802.11ac WiFi Gigabit Router, model no. RT-AC87U, for $144 with free shipping. That's $87 under the lowest total price we could find for a new unit, although we saw a refurb for $10 less in June. It features data transfer rates of up to 2.4GB/s, four Gigabit LAN ports, and USB 3.0. Deal ends October 5.
Note: A 90-day warranty is provided, although it is unclear who backs it.