The price I gave you is what one of our customers pay, after negotiation. True, they didn't order for 100 TiB.
In 2011, you don't need 150 nodes to build a 100 TiB system.
Don't take this as an official estimate, but I think we would advise on 7200 drives and more RAM and it would probably end up with a system one (several?) order(s) of magnitude faster than what you would get with a regular RDBMS.
Good luck with that. At $100 per 8GB of ECC RAM, that's $1mil in RAM, and with 4-slot machines you'll need 3,200 boxes. 1,600 boxes if you go for dual-CPU machines with 8-slot.
First, 8GB ECC sticks are actually a bit under $100... retail. You're not going to buy almost 13,000 sticks of RAM retail, are you?
Second, server motherboards are not limited to a mere 8 slots. 16's are widely available, even 32's can be found at retail, and there are more options out there than what Newegg or whatever you're shopping at has.
In 2011, you don't need 150 nodes to build a 100 TiB system.
Don't take this as an official estimate, but I think we would advise on 7200 drives and more RAM and it would probably end up with a system one (several?) order(s) of magnitude faster than what you would get with a regular RDBMS.