A few words on the backstory behind high resolution, lower priced monitors... The panels in these displays are made my LG, a very reputable manufacturer. But making large S-IPS panels like this is not easy; the process is fraught with manufacturing challenges that causes a fairly high percentage of them to have some performance defects (dead or stuck pixels, color bleeding, spotting, etc.). Companies that buy large numbers of panels from LG (e.g., Dell, Apple,...) inspect production runs. They do this by selecting a random sample from the batch and testing them. Big companies have very high standards and therefore reject a lot of batches of panels. When they do select a batch remember that there could be a few rotten apples in the "A+" batches since they don't test every panel (which explains why some poor folks get defective Apple Thunderbolt monitors); but in general they choose and deliver the best. And guess what... you pay for that!
LG doesn't throw rejected batches away, they sell them to other manufacturers of monitors. Even an "A" or "A-" batch, that was randomly sampled and rejected by the fat cats, still have many, many "A+" panels mixed in; there are just fewer of them. Manafacturers take these "rejected" batches and produce some superb monitors at prices one-quarter to one-third of what the big boys charge. Some retailers of these second and third tier panels take another step. They will test each panel searching for the "A+" units among the "A" and "A-" shipment. These are selected and offered as "perfect" units that are guaranteed to not have stuck pixels or large amounts of color bleeding. These are offered at higher prices, though the premium they charge is pretty fair considering they take time to test each monitor. So these monitors are nothing to scoff at - they're basically the same panels. Another thing to consider is that the 'panel' is not the only thing inside a monitor. The power supply that drives it and the electronic components built around the panel to make the display function properly represent a whole other set of choices you're buying into. For example, many manufacturers use cheap capacitors that will fail just out of warranty that will cause your display to falter. So the big boys don't only select the cream-of-the-crop panels; they also tend to use better components, and create more features, when they build their monitor.
What you're trading with these less expensive monitors is getting a much lower price while running the risk of getting some stuck/dead pixels, and longevity of the device. Since the technology is changing so rapidly longevity might not be all it's cracked up to be. And if you're willing to pay a slight premium for a unit that was tested for defects (like stuck pixels) you stand a very good chance of getting a super deal on a monitor that looks just as good as what Dell or Apple will sell you. Be advised that most of these monitors have a glossy surface and do not have much of an anti-glare coating. To me this is a bonus. Very high resolution monitors don't look that great with AG coatings (I personally thing the Dell Ultrasharp monitors look terrible; Apple wisely chose to leave things glossy).
All-in-all, if you know the facts and search carefully for the right product offering you'll get a very good deal and walk away happy indeed. These monitors are amazing in their clarity and are well worth the price.