Getting 9TB of EBS on top of that puts the bill at $1516 per month. None of that accounts for traffic, of which we know nothing about.
The thing is in an Amazon world, you could optimise the setup for an Amazon deployment. For example, you'd probably move parts of that data, like database snapshots, onto S3.
Those costs are still nothing to sneeze at, and very likely suboptimal.
You also aren't accounting for redundancy. If the machine totally blows up, how quickly can you build another? Or do you spend +5k to have a second sitting as a standby? If the hardware does fail (whether it's a single drive in RAID or the whole system), who fixes it (or deals with getting it fixed)? For that matter, is the person who built or sourced the hardware's time worth $0?
Cloud IS more expensive, but it's not as simple as comparing to the up-front cost of one piece of hardware.
How much of this is actually utilized? O.o
I think the whole HN dataset is well under 100GiB, and maybe even under 30GiB.
As an aside, I went to look at some of your old posts and got this:
Secure Connection Failed
The connection to the server was reset
while the page was loading.
The page you are trying to view cannot
be shown because the authenticity of
the received data could not be verified.
Please contact the web site owners to
inform them of this problem.
Thanks the website has been taken down.
Detailed specs have been written before, try searching.
FreeBSD is the OS of choice for them.