Interestingly, there were some cheap Korean 27" 2560x1440 displays that came to prominence recently, mainly because they were originally selling for ~$370. The panels themselves are the same as those in the 27" Apple and Dell displays, just ones that didn't meet Apple and Dell's requirements.
You can search for "Yamasaki Catleap", if you're curious about it.
You can search for "Yamasaki Catleap", if you're curious about it.