Tanga offers the refurbished Asus T-Mobile CellSpot Dual-Band 802.11ac Wireless Gigabit Router, model no. TM-AC1900, for $45.99 with free shipping. That's $4 under our December mention of a refurb and the lowest total price we've seen in any condition. (It's a current low for a new unit by $36.) It features wireless data rates up to 1.3Gb/s, dual-band support, and prioritizes WiFi calls.
Note: No warranty information is available, although the seller does offer a 15-day return policy.