The Acer Predator XB3 is a whopping 66% off at B&H. It may only be 1080p, but IPS and 300Hz at this price is a steal.
You can get a 27-incher for $400, 34-incher for $500, or a massive 39-incher for $700. All of them are massively discounted new monitors.
If your new monitor looks underwhelming, its default settings are probably the culprit.