4k helps a lot with tiling tables
the last one you linked is not 4k,
QHD is 1440p, 4k is 2160p
https://www.dell.com/en-us/shop/ultr...or-accessories
seems to be reasonable among the other options on that site... even tho you can get 27" 4k monitors for 250$ on amazon but hey you got credit there and I'm sure it's a nice monitor and all
the 900$ one was just ridiculously expensive, that's prob for image and video professionals, ppl who need super accurate colors and extra features you won't use