Typically clients requiring that much SSD-backed storage have performance targets and a very specific workload, so this affects options along with pricing. With that said, ballpark for what Amazon is advertising is comparable to our pricing, except with us you are _guaranteed_ the resources whereas they are using a multi-tenant environment (you're not using the only instance on their host and your I/O is influenced by everyone else using that host).
I haven't downvoted (and in fact couldn't if I wanted to since you replied to me), but personally my issue with your comment is that you're being as vague as your website's prices. Would be more interesting and relevant if you actually gave a price for a box comparable to the AWS specs.
This assumes Amazon is using SLC and not MLC drives, which are considerably cheaper. Also, the quote above is from SoftLayer I believe, which is not the cheapest provider for high end hardware.
EDIT: Downvoted? Please offer your point of view.
EDIT2: Sample pricing offered in comment below.