Amazon.com has 27″ LG 27UK850-W 4K HDR IPS USB-C FreeSync Monitor on sale for $405.52. Shipping is free.
Specs
Resolution: 3840×2160 (4K UHD)
Refresh Rate: 60Hz
Response Time: 5ms
Viewing Angles: 178/178 degrees
HDR10 FreeSync sRGB 99% color gamut
VESA Mount: 100x100mm
Ports:
1x USB-C (4K Video Data Charging)
2x USB Type-A
2x HDMI 2.0
1x DisplayPort 1.2