Buy.com via eBay offers the Dell 28" 4K LED-Backlit LCD Monitor, model no. P2815Q, for $499.99 with free shipping. That's tied with a deal from six days ago, since expired, for the lowest total price we've seen (It's a current low by $21.) It features a 3840x2160 native resolution (four times that of 1080p), LED backlight, and HDMI input.