Why bother with S3? I'd buy a Raspberry Pi, plug it in at home and call it a day.
At 5 Watts and $0.30 per kilowatt-hour, a Raspberry Pi would cost $1.08/month to run.
With 1 free GB and $0.09/GB-month, S3 would be able to deliver 13 GB/month at a cost of $1.08/month.
So, RasPi at home gives you "unlimited" egress and a fixed cost, but you have increased latency, a rather small outgoing bandwidth (most likely), and all the downsides of running your own server.
S3 gives you unlimited bandwidth, low latency, and no server maintenance, but it's only competitive on price if you don't exceed 12GB of egress.
Overall I prefer S3, even if I think their egress prices are ridiculous. RasPi at home has some geeky cool factor, though...
NOTE: $0.30/kwh is basically what I pay (California) for any additional usage. These equations will favor home hosting if your electricity is cheaper.
Especially with the site being considered in 'maintenance mode', I doubt they want to manage a server aside from the other things they need to do.
I don't know how I'd feel about a public resource being at the mercy of some user's comcast connection.
You can buy a hosted moral equivalent of an RPi for peanuts, e.g. https://www.scaleway.com/pricing/.
That said I'd agree, Raspberry Pi's a great but not quite fast enough for serving a high-traffic website.
For example, what pages get accessed the most anyway? I'm guessing the latest source code and maybe the latest release, though most people probably just apt-get git instead so it's probably mostly the source code. Then there are man pages and some other info pages, if I remember correctly. Sounds like the latest release + 90% of those text pages can easily fit in RAM. So memcached? Nah, the Linux kernel happily caches the files that you read from disk.
I don't know the actual numbers but it doesn't sound infeasible to me. A $230 hosting bill is very heavy though, I guess you'd need some serious fiber as well to provide the uplink. But again, without numbers it's all "maybe" and "probably".
Nowadays I would have used a VPS for that. The point with S3 or any other cloud solution is that they make sure you're up and running. Even though it might still be useful, the need for good service monitoring is as good as gone when moving to one of these cloud based platforms. And then I'm not even taking into account the time you have to invest in setting up and configuring a RPi properly vs just pushing a repo to Github Pages, or uploading a zip file to S3.
Heroku or other cloud platforms can be crazy expensive, but for static file hosting, S3 or Github Pages is more than enough and quite affordable.
I've just checked and it looks like they nolonger do so though...
$ curl -I https://www.raspberrypi.org 2>/dev/null | grep X-Served-By
X-Served-By: Blog VM 2