Green-Sum via eBay offers the Yamakasi 28" Perfect Pixel 4K 2160p LED-Backlit LCD Ultra HD Monitor, model no. M280PU, for $269.90 with free shipping. Excluding other eBay vendors, that's $111 under the lowest total price we could find for a similar monitor elsewhere and the best deal we've seen for a 28" 4K UHD monitor. It features a 3840x2160 (2160p) native resolution, DisplayPort, and three HDMI ports.