From memory, it was for Joint Academic Network. I'm surprised the Wikipedia article doesn't mention it at all, but it seems hard to find an authoritative source.
A handful of peanuts a day to avoid dying in the event of (accidental, inadvertent) exposure sounds like a pretty good deal! I think that's the value here:
> "It's a wonderful feeling," Chris says. "I'm no longer afraid of dying."
It costs money to serve S3 objects out to the internet though. S3 GET request billing + the usual AWS egress fees, after you've burned through the free quotas. Egress is currently $0.09 per GB + tax.
It seems like a good move. The Tao was a big single document with heavyweight edit/revision burden, which probably made more sense when it was updated by publishing a new RFC, as if it were a print publication.