My computer is at least 12 years old by now and according to the Steam hardware survey the majority of people on Steam has a PC that is worse than the Steam Machine. I might get one as my new desktop if the price is not too high.

For my server I bought a domain on loopia.se and pay for no other features than the domain name. On the Loopia website I then changed the DNS nameserver to Cloudflare and use a script to update the IP of my network. Cloudflare has some package you can install on Linux to update the IP but I never tried it.