Walmart offers the refurbished Vizio SmartCast E-Series 49.5" 4K 2160p LED-Backlit LCD Ultra HD Smart Television, model no. E50U-D2, for $299.99. Opt for in-store pickup to drop it to $293.09. That's $107 under a new one and the lowest price we've seen in any condition. (It's $125 under the new one we saw three weeks ago.) It features a 3840x2160 (2160p) native resolution, full-array LED backlight, 802.11ac wireless, Chromecast, USB, and four HDMI inputs.
Note: It lacks a tuner. You'll need to buy one separately to watch over-the-air broadcasts.