Walmart offers the refurbished Samsung 55" 4K 2160p WiFi LED-Backlit LCD Ultra HD Smart Television, model no. UN55KS800DFXZA, for $699.99. Opt for in-store pickup to avoid the $49.97 freight charge. That's tied with last week's mention and the lowest price we could find for a refurb by $80. It features a 3840x2160 native resolution (4K), WiFi, USB, Ethernet, Smart TV apps (Netflix, Amazon Instant Video, Android games, etc.), and four HDMI inputs.
A 90-day warranty applies, although it's unclear who backs it.