Amazon offers the TCL 55" 4K 2160p WiFi LED-Backlit LCD Ultra HD Roku Smart Television, model no. 55P607, for $599.99 with free shipping. That's $200 off list and the lowest price we could find. It features a 3840x2160 (2160p) native resolution, content streaming via Roku TV (Netflix, Youtube, Hulu Plus, more), 802.11ac wireless, and three HDMI inputs.
Note: It usually ships within two to three months.