He won't find any. Quality 1440p 144 hz+ IPS displays (with G-Sync especially) don't go for that low. And by quality I mean brands like MSI, Gigabyte, Viewsonic, Asus etc.
Also, some of the used market prices are out of their minds. Prices of new monitors are falling hard and you can buy an Asus 180 Hz 1440p IPS monitor for ~100K. And an Gigabyte M27Q-X 240 Hz IPS 1440p for ~135K.
And AFAIK there are no comprehensive reviews for EASE brand or other cheap monitors, not saying they're bad, but we simply don't know if they're any good. Even some quality brand monitors are pretty bad. Therefore no point in spending money on those unless you're desperate.