Edited March 27, 2019
at 05:03 AM
Lenovo is having a sale on their monitors, this one is currently $275 but $248 with coupon code MONITOREXTRA10, then ~$270 after taxes depending on your location. This is the cheapest 27 inch IPS panel with 1440p resolution and VESA mount I have ever found.
There is also the Lenovo L27q 27" Monitor for $239 but without the VESA mounting points or USB-C.