Walmart offers the refurbished LG 55" 4K 2160p WiFi IPS LED-Backlit LCD Ultra HD Smart Television, model no. 55UH6090, for $488.99 with free shipping. That's $100 under our February mention for a new one and $61 under the lowest price we could find for a refurb. It features a 3840x2160 (2160p, 4K) native resolution, LED backlight, Smart TV apps (with access to Netflix, Youtube, Hulu, etc.), USB, and three HDMI inputs.

Note: No warranty information is available, but the seller offers a 90-day return policy.