Monoprice offers its Monoprice CrystalPro 28" 4K 60Hz LED-Backlit LCD Monitor, model no. 12156, for $399.99 with free shipping. That's tied with our June mention, $399 off list, and a very low price for a 4K display that runs at 60Hz. It features a 3840x2160 native resolution (four times that of 1080p), 60Hz refresh rate, LED backlight, audio passthrough, DisplayPort, and HDMI.

Note that the 60Hz refresh rate is supported only on the DisplayPort inputs.