Madness?
http://www.stomptokyo.com/reelopinions/uploaded_images/300-1-770608.jpg
THIS IS ENTHUSIAST CLASS!
In all seriousness, the price is a tad high, but not by much for what you're getting. As erixx stated, the aluminium panels on this are 2-4x as thick as other high-quality aluminium cases.
Couple that with the fact that this case oozes personality and innovation, and $350USD seems fair to me.
I seem to remember when the original Cosmos came out that people were complaining of the $300 price tag. Look how many people have a Cosmos now, and how many other cases now have features that were either started by the Cosmos or brought mainstream by it. If a case is innovative and sturdy, people will pay whatever price is asked. Hell, there are still DangerDen torture racks floating around. The base model for a torture rack was what, $150-200? Add a cover and some 120mm fan mounts and it's now $250-300 for essentially a large chunk of plexiglass with the DD logo. Not everybody thinks strictly form, fit, and function like you and I. Fashion plays a large role in a lot of people's decisions. Bottom line, it's their money, not ours. As much as I like this case, no bloody way I would pay more than $200 shipped for any case. I didn't even pay $100 for the case I'm using now that's housing nearly $2k worth of hardware, and frankly, I love it.
Edit: Went back and looked at some of erixx's pics again and he has a Cosmos. Irony!