Ending today, Monoprice offers its Monoprice Premium Series 28" 4K Ultra HD LED-Backlit LCD Monitor for $349.99. Apply coupon code "BIG20" to cut it to to $279.99. With free shipping, that's $70 off, $36 below our January mention, and the lowest price we could find. It features a 3840x2160 native resolution (four times that of 1080p), built-in speakers, and DisplayPort, HDMI, DVI-D, and VGA inputs.

Note: This code can only be used once per account.