Consider one of the newer NEC monitors. The MultiSync P200 series are great performers in color and accuracy. The cost in the United States for these is well under $500US, in fact under $400 for most models. There is the P221 that I have just started using part of the time and for most photo work I find that it compares very favorably to a couple of multi-thousand dollar units that are 1-2 years old.

The NEC does not have lots of 'features' with connectivity or added outputs like a USB hub, but it does produce a great image.

Avoid the NEC Accusync's for photos at this time. They may improve but the color is 'shifty' and they don't calibrate consistently.

Look for a contrast ratio around 1000:1. Anything greater than this is not very realistic as a spec or is 'dynamic' or 'active' and is important to video or gaming but doesn't really affect still image editing greatly.

A monitor that can be rotate to landscape or portrait mode is also a big plus and you won't realize how handy this is until you don't have it!!

Do include the NEC monitors on your list as possibles. I almost exclusively used NEC's in the CRT days because of value. They also were some of the most stable products in terms of color and intensity. Now they've finally started to sell LED units that I believe will match up to their older products.