Walmart offers the Panasonic 55" 4K 2160p 120Hz WiFi LED-Backlit LCD Ultra HD Smart Television in Silver, model no. TC-55CX420U, for $599.99 with free shipping. That's $301 under our January mention and the lowest total price we've seen. (It's a current best by $228.) It features a 3840x2160 native resolution, LED backlight, 120Hz refresh rate, WiFi, Smart TV apps (including Hulu Plus, Netflix, and YouTube), USB, and three HDMI inputs.