My experience has been different I guess. I run a small web-based business serving around 50,000 visitors a day. We don't do anything particularly bandwidth-intensive, but we spend less than $500/month on our server and bandwidth.

This guy's traffic would be considerably lower than ours I would think. Most of his resources are going to be going to the scanning effort. But that can run at a continuous rate around the clock, which is the most efficient way to utilize resources. And it doesn't need to be done completely quickly: it looks like he'd be fine completing a full scan in under a month. That shouldn't require particularly high-powered hardware.

So, I can't imagine this guy could possibly be spending more then $100k/month on hosting. Honestly I would be surprised if it was more than $10k. I was just trying to clear up what I saw as a misconception.