Seiki 42" 4K 2160p LED LCD UHD TV for $298 + free shipping
H. H. Gregg offers the Seiki 42" 4K 2160p LED-Backlit LCD Ultra HD Television, model no. SE42UM, for $298 with free shipping. That's $202 off and the lowest total price we could find. It features a native resolution of 3840x2160 (four times that of 1080p TVs), LED backlight, USB, and three HDMI inputs.
2 very similar deals were also reported by some other sources: