BuyDig via eBay offers the Dell S2817Q 27.9" 4K LED-Backlit LCD Ultra HD Monitor for $219.99 with free shipping. That's the best deal today by $177 and within a buck of last month's mention, which was the lowest price we've seen. Features include:

3840x2160 (4K) native resolution

dual 9-watt speakers

USB 3.0, DisplayPort, mini DisplayPort, & 2 HDMI inputs