If Moore's law holds and you're willing to wait a month instead of ~9 days, it costs <$1500 in hardware, and you can keep/resell that. Or, again, rent time. Or

If Moore's law holds and you're willing to wait a month instead of ~9 days, it costs <$1500 in hardware, and you can keep/resell that. Or, again, rent time. Or just use a distributed.net-esque approach and bruteforce using (a lot of) standard PCs. Or... Seriously, "people aren't going to hack us" is the new "premature optimization is the root of all evil": a convenient excuse to do it horribly wrong.