Walmart offers the refurbished Samsung 55" 4K 2160p WiFi LED-Backlit LCD Ultra HD Smart Television, model no. UN55HU6950FXZA, for $639.99 with free shipping. That's $240 off list and the lowest price we've seen. It features a 3840x2160 (2160p) native resolution, WiFi, Internet apps, USB, and four HDMI inputs.
Note: No warranty information is provided.