I think you mean 150 thousand.
That aside, I think that RAID is a terrible way to do this. Rabin's Information Dispersal Algorithm is a much better bet. The maths behind it let you split a file into n shares, with any k of them being sufficient to reconstruct the original (with n >= k). The advantages are many, but one of the more interesting ones as it relates to this discussion is that it can blur the lines between cold and hot storage. If you have some number of shares (say 'h'), close to k in "hot" storage, then you only need to spin up k - h cold storage silos to reconstruct the file.
With a regular storage system, I guess you'd want to cache the full replica once it's been recovered from the cold storage silos. With IDA, you can dynamically scale this by creating new shares, each of size 1/k and spread these out over your hot (cache) nodes. This is much more efficient than creating full-sized copies (replicas) both in terms of storage (entire system takes up n/k times the size of the archived data) and availability (since we can select any k silos for load balancing, or request from more than this and just use the first k to arrive back if you want to minimise latency).
I actually use this scheme on my home network. I've got a k=6,n=10 system for archival purposes. Six of the ten machines/disks are usually asleep, and I've got 4 always on. So when I want to retrieve something I can choose which two of the sleeping machines to wake up (with wake on lan) or power up their drives (by a software signal). Once the machines are up, I just have to pull across two shares for each file I want (each 1/6th the size of the full file). I can cache these shares for as long as I think I might want to have access to the file. Admittedly, I don't have a fancy management interface for doing this (just scp wrapped up in some simple scripts), but it works really well for me, only takes up 1.6 times the original space (as opposed to RAID, which will probably be 2x) and still tolerates 4 (near-simultaneous) disk failures before the data is lost.
RAID definitely has a place for things like OS disks and hot data (work files and so on) but I think that IDA definitely wins out for archival and "warm" (not so hot, not so cold) data.