"You get what you pay for" applies to many things, but not all.
The QNIX (single input), and its many variants and rebrands, is extremely popular for a reason. It uses, typically, a complete samsung 27" QHD panel and backlight. Its then put into a cheap ass casing with an adequate PCB. You get nothing else.
But what you do get is excellent picture quality (yes, better than other budget name brand stuff +$200 more non sale prices) . This is explained ad naseum in 1000 page threads elsewhere on the internet if you choose to look into it.
Cons: Possible minor "backlight bleed". If you choose, you can fix this by removing the metal frame around the panel and bending it square. Sounds bad, but it isn't
Cheap casing, including tilt.
Tedious warranty process if required
DVI D only. Do not buy the others
Pros: $300 shipped in one day. High quality display. You just wont beat it for the price
Overclockable. 96 hz minimum, 120 possible. Even if you cant push those frames, this decreases input lag as well. Input lag is stellar due in part to the simple PCB.
So on one hand, all the important things are there. On the other hand, its some ebay reseller out of Korea. Korea, who makes the good shit to begin with mind you, but its a long shot from customer service at a domestic office for a major company
Worth it, in my book. The only 1440p monitor I want above this is a gsync monitor, I feel it would be a total waste of money for most anything in between