General questions about monitors

I finally joined the forums after just watching the videos for a long time so I just wanted to say hey! :D

Anyway I've been curious about monitors and how they fit into the market now a days. So I've been curious about 1440p monitors and why they're so expensive when we are starting to get stuff like this now.

Samsung 4K w/ 1ms response

I know that 4K monitors for the price do usually have some kind of quirk or just a problem in general and that is apparent in this particular one but to me this shows that those problems will get ironed out as time goes on.

Is it even worth it to get 4K at this point? Also with 4K monitor prices dropping so rapidly it seems and they get so accessible then why do 1440p monitors remain at a similar price anyway?

I've been curious because I'm looking to get another monitor and use my current 1050p as a secondary. I do video/music/photo creation & editing so you can see where I am coming from. I won't be gaming with it.