Always find this site useful.
https://www.productchart.co.uk/monitors/. You can be more specific about your requirements here.
Personally, I have the Pixio P277 Prime Gaming monitor. 27inch 1440P 165Hz and I got it at a discount for £280. I think you might struggle to find your options for a good 1440p in the 150-200 price range, options are rather limited.