Nighthawk X4S AC2600 4×4 MU-MIMO Smart WiFi Gigabit Router for $199.99 shipped.  Here is a screenshot for reference.  This router has been ranked #1 in AC2600 performance by Small Net Builder and features a high-speed 1.7GHz dual-core CPU, along with two USB 3.0 ports and one eSATA port.  Most places have it for about $267.