Now, as you mentioned that you need a 27" 1440p 144Hz monitor, I assume that your primary requirement is gaming. Around $300 this seems to be the best option:
VIOTEK GN27DB (Curved)
I have never used any VIOTEK monitor before, so I'm just recommending this based on reviews available on Amazon. Also, I would suggest you read all the reviews by yourself once. It's a 1440p VA panel. You will notice a quite difference in colors and viewing angles if you are coming from a TN panel.
Moreover, here is another option that should work for you in the $300-$400 segments:
Acer XG270HU omidpx
It's an excellent option to consider over VIOTEK if you don't need a curved screen. Acer XG270HU is a TN 1ms panel that is pixeled at 1440p. You can expect better response times and fairly good colors.
These are the best monitors that perfectly fit your requirements according to me; also you can read in-depth reviews of them online or watch videos on YouTube for much better understanding.