Walmart offers the refurbished Samsung 54.6" 4K 2160p LED-Backlit LCD Ultra HD Smart Television, model no. UN55JU6500, for $549.99 with free shipping. That's $163 under our February refurb mention and the lowest total price we've seen for this TV in any condition. (It's the best deal for a refurb now by $150 and $648 less than you'd pay for a new one.) It features a 3840x2160 native resolution (four times that of 1080p TVs), 802.11ac wireless, Smart Hub (with access to Netflix, Hulu Plus, Pandora, Amazon Video, more), USB, and four HDMI inputs.
Note: No warranty information is provided.