If you want to buy cheap display, there is almost none difference between low-end displays - in case of of displaying things. (differences are only in ergonomy, design, …)
However, there is few of them where is difference really noticeable.
For example, my shopping in Planeo:
There was about ten low-end displays (20 - 23 inches) including Ausus, LG, Acer and BenQ. Their price was something like from 3000 up to 6000 Kč (120 - 240 €).
There was almost unnoticeable difference in their poor displayed images. However, there was one really different from each other (including other LGs!).
It was LG W2043S-PF 20.1’’. Against others, it has outstanding contrast and great view angles. Color rendering is also slightly better.
From these I’ve seen, LG W2043S-PF displays image that good as three-times more expensive displays. In Czech, it can be bought for ~2700 Kč. (108 €; see Zbozi.cz).
Beware, there are two models of LG W2043S-PF - model A and model B. One is only D-sub capable (analog) and other one has also DVI (digital).
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Rozdíl v obrazu tam byl jak když do řady postavíš 9 spojenckých fieldů (černoši) a jednoho osáckýho medika (árijec). 
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