If you want to write things on a self-hosted static blog in your free time, the hosting costs add up to a few dollars per month for a domain name and (e.g.) a VPS, for something that can scale to thousands of simultaneous readers. This is completely negligible, so I don't think "the bill" is a very important factor.
We already do. The hard disks, the bandwidth, the electricity.
Give me a ready-made virtual machine image [1] pre-configured to share files. I don't care about the protocols, I don't care about super-duper-unbreakable encryption because I won't share or host copyrighted content nor wombat porn.
[1] Not a freaking docker image or whatnot (hi, Mediagoblin!) - if you want it to succeed it has to be dead simple so that mere mortals can do it.