I know its a Freesync Monitor but it was the ONLY NEW(Not Refurbished) 1440p 144Hz Monitor on Newegg for $300 or less.
Monoprice 24-inch WQHD 144Hz $242
https://www.newegg.com/Product/Product.aspx?Item=9SIA8SV7434952
It was a great monitor when it came out about a year or so ago and is still a great choice.
Here is a great alternative:
(Refurbished)Pixio PX276 27" Wide Screen Bezel-less Display 1440p Gaming Monitor Professional Adaptive Sync 144Hz $299:
https://www.newegg.com/Product/Product.aspx?Item=9SIAB717894218
Still a great monitor, little bigger then the cheaper one above, IPS screen so it has better color accuracy over the VA panel above.
The bottom monitor is the one I would get if I had to choose between the two options I gave.