Now, the 8-slot case looks like really sweet deal.

My rigs are 7 Vega cards with homemade case, and the costs are:

Motherboard: 150$
Ram: 8gb sodimm: 40$
SSD: 128gb mini sata: $50
Power supply 1200W, breakout board and 17x power cables: 100$
Wooden and aluminum parts for case: $20

total: 360$ + time effort to make the case.
So this nice looking case is just a little bit more than my DIY solution, having much bigger PSU but a little bit less ram and ssd. I wish there was such a deal when I was building the rigs, but now it doesn't make sense for me, only if i was going to build new rigs.