Cosmos used to be around $345, now as the supply diminishes they will rise, it is just like the Corsair 800D (and I love this case due to the 4 hot-swap drives) and I think the 800d is way better then the 900d, and for the 800d you pay the price. I built a system for a client with a Cosmos, and I will admit it is a very nice case, but once they get past $350, look else where.
If you can find the Ethoo Primo at around $365--400(Max) or if you can order one with out fans (sometimes it happens, I got one) it drops it by $100 go for that. BUT, and I do mean BUT if you are willing to make an investment, look at a CaseLabs, they will cost you WAY more then a normal case, but damn you will be impressed. I was.
I also think Silverstone and Lian-Li make some great cases.
There are good cases out there it will take a bit of research, but Bitfinex has the Shinobi XL, Phanteks has the Ethoo's line, Corsair has the D line, Silverstone the TJ line, Lian-Li about any of their lines, and CaseLabs all there stuff.
You have to think about what you want and what your willing to spend. Simple as that.
Peace.