Walmart offers the refurbished Sharp 49.5" 4K LED-Backlit LCD Ultra HD Smart Television, model no. LC-50N6000U, for $349.99 with free shipping. That's $130 under our mention of a new one from last July and and the lowest price we've seen for it in any condition. (It's the best deal by $50 for a refurb today.) It features a 3840x2160 (4K) native resolution, WiFi content streaming (Netflix, Youtube, Pandora, more), USB, and four HDMI inputs.
Note: No warranty information is provided, although the seller does offer a 90-day return policy.