I'll just chime in here with a few comments since I have a nice expensive screen at home, yet I have a cheap Dell IPS screen at work.
My home monitor (NEC Spectraview 2690WUXi) is pushing 8 years old and still looks as good today as it always did. After 4 years with my company I'm on my second Dell monitor and that one is also de-laminating now. At this rate in 6 years I could afford the monitor I've already had for 8. Score 1 for quality.
My home monitor has a builtin colour lookup table (yeah features blah blah blah). My Dell at work if I were to connect a calbrator to it, the more of a correct I apply the worse gradient banding will get as the video card output gets limited for the sake of colour correction. It's a very warm monitor so if I calibrate it to 6500k the result is actually a severely crippled red channel on the video card. This IS noticable. Score 1 for quality.
My home monitor is wide gamut. Photos involving sunsets and clear blue oceans I take look fantastic. They get quite a bit duller when I set them back to sRGB for display on the internet. Most cheap monitors are sRGB. This is only good for viewing your own images at home but hey that's what I do, that and print in which case wide gamuts also help. This has plusses and minuses but since I'm gunning for team good monitor I'll say again score 1 for quality.
I won't even comment on non-IPS displays. Suffice to say that my girlfriend edits on a laptop and then comes to my screen to fine tune and is usually not happy with the brightness of her original edits, no surprise given the viewing angle issues TN panels introduce.
Can I print an image for you that you will definitely say "Yes this one came from the good monitor?" No. Our eyes are great at comparing but horrible at noticing initial problems to begin with.
Can you compare prints to cheap and expensive displays and say one display does a much better job than the other? Yes.
Is it nicer working on an expensive display with perfectly even backlighting and accurate calibration? Yes.
Is it worth the money? Well that's the question of the day. If all you're buying is cheap Dells I'm going to go with No, but only you can answer that.
Is your doctor looking at your CT scans on a cheap monitor? Well then your choice of monitor won't matter since you won't live long with his medical advice
