There are a number of factors that go into play (did the site use custom SSL, what edge locations were they providing caching in, etc), but had Kreb been a norm

There are a number of factors that go into play (did the site use custom SSL, what edge locations were they providing caching in, etc), but had Kreb been a normal paying customer, this could easily have been a over a million dollar bill (if it was sustained long enough to alter his 95th percentile bracket) in the cheapest case. If things like custom SSL are in the mix (which Akamai charges absurdly high prices for), or lots of traffic from more expensive POPs, or lack of already having pricing commiserate with high volume traffic commitments, the bill could've been 5-10x that amount or more.