TN panels are cheap.
VA = mid-range quality.
IPS are good, but pretty expensive.
OLED are technically the best, but they are very expensive.
This is not 100% correct.
It's at best a general guide, but is in no means 100% correct.
TN panels are usually cheaper, and in the past used to have unuseable viewing angles, and colors that didn't even resemble themselves. nowadays, a good TN panel can have useable vertical viewing angles, and pretty good horizontal ones, and while not enough for color accurate work, the colors on a good/calibrated TN panel are enough to not be noticiably bad, but the upside of these TN panels, is their very fast response times, making old 240hz monitors be exclusive to TN since on an IPS of say, 6 years ago look like a smeary mess as 240hz, if it even hit that.
VA panels are not worse than IPS, and aren't cheaper in most cases. They are different.
VA is made by samsung, while IPS displays are made by a lot of companies, though the best ones usually come from LG.
VA has pretty good viewing angles but not as good as IPS, and usually have great colors, sometimes even better than IPS. Their 1 major pitfall is their response times, which is usually quite bad, though recently with the Odyssey g7 and g9, they became much better, and 240hz actually looks pretty decent with no major smearing.
IPS panels have the best viewing angles, and good color, though their response times are just or even worse than VA, and 240hz on them is still in it's infancy (They are like, 3 IPS 240hz monitors, and none have very good response times without tricks like backlight strobing).
OLEDs are not the best. They are the most expensive, yes, but they have a very large list of both pros and cons, all of which are major:
Pros:
Amazing color, The best contrast (since black is actually the pixels turning off, unlike a traditional LCD that has a backlight, making black look gray), and even see-through displays, foldable displays and more are all available due to oled.
Cons:
Expensive, Low brightness, and of course, burn in.