As one of its daily deals, Woot offers the refurbished Samsung 28" 4K Ultra 2160p LED-Backlit LCD Monitor, model no. U28D590D, for $339.99 plus $5 for shipping. That's $94 under the best price we could find for a refurb, $154 under the lowest price for a new one, although we saw a refrub for $15 less in spring. It features a 3840x2160 native resolution (four times that of 1080p), LED backlight, two HDMI ports, and DisplayPort. Deal ends today.
A 90-day Samsung warranty applies.