I can't imaging how bad the pricing out of most consumers will be with these.
You have to think about the cost of storage in terms of the cost of the data you restoring. What do you bill clients per hour and how many hours of video fit inside this RAID unit?
I suspect if you do the math this is not a big cost item.
If you are a no-budget shooter like me, then you don't needs this. What I do is get a small 120GB SSD drive for the video data I'm working with. Then later archive and backup to bare SATA drives I keep in a fire safe.
The $125 is faster then this Thunderbolt disk array. The only disadvantage is that it needs tone cleared out when a project is done.