I concur.
It depends on your end output & display media, the size mostly:
1) Do you print your own work ? If you do, you will want a fairly color-accurate monitor to work with the printer. There are a whole lot of courses on workflow, color space, etc.
2) If you use third party printing service, use their color profile & soft proof before sending the files.
3) If the photos are only used for digital display, ie: cellphone, tablets or online forums, most sub-1K monitors are adequate.
4) If you venture into videography, a 27" 4K monitor or better still, dual monitor set up would help.
The monitor landscape is a strange world, there are sub-600, sub-1k and 4~5K models; for color-critical works, Eizo monitors are mostly good for photography, albeit some people find the brightness lacking.
Good luck in choosing your monitor.
Oliver