With a 4K resolution, HDR support and additional features like USB-C and a height-adjustable stand, the 27-inch Samsung S80UA UHD monitor is almost a steal at a price of only US$279 on Amazon.
https://www.notebookcheck.net/Deal-Samsung-S80UA-27-inch-4K-HDR-monitor-with-USB-C-now-on-sale-for-US-279.594164.0.html