If I was to take a guess on why the Khaos is so expensive, I would say it has to be the solid aluminum design. But there is one huge glaring problem with this, and I cannot make any sense out of it.
NZXT is obviously targeting gamers and hardcore users with the Khaos, there is little doubt about that. In doing so they decided to make a 100% aluminum case as they are more desirable for its lighter weight and therefore ease of transport. However on the disadvantages side, they are usually more expensive and far less durable, as aluminum bends and dints far easier than steel. It would seem that NZXT has understood this to a certain extent.
In order to counter the durability issues that aluminum presents, NZXT has simply doubled and even tripled the thickness of the case, effectively eliminating any weight advantages and evidently sky rocketing manufacturing costs.
As I alluded to earlier in the review, the NZXT Khaos is roughly the same size as the Thermaltake Armor+. The Armor+ costs half as much and weighs just 2.3 lbs more, which accounts for nothing when we are talking about 35+ lbs. cases. The Armor+ is constructed from 1mm thick steel, so it has no durability or cost issues. And so from this point of view, NZXT would have been far better off creating the Khaos out of 1mm thick steel, allowing them to compete in the $200 price range.
But putting this aspect aside for a minute, the build quality of the Khaos is just average and the design seems quite poor. There is nothing clever or different about this case, no screw-less design features, no cable management, nothing. So what you are getting is your run of the mill full size ATX case, and even then for a full size case the interior seems very crammed. There is absolutely no room left when installing a graphics card the size of the GeForce 9800 GTX, for example, while I can park a car behind a 9800 GTX in the Armor+. Overall the NZXT Khaos fails to deliver.