Cheap. I mean, expensive by the standards of 1994, but -- inevitable comparison inbound -- a Raspberry Pi 4 has more CPU, more IOPS, more storage, and more RAM

Cheap. I mean, expensive by the standards of 1994, but -- inevitable comparison inbound -- a Raspberry Pi 4 has more CPU, more IOPS, more storage, and more RAM than many a 1994 small-ISP Usenet server. And modern Linux is a heck of a lot nicer to work with than any of the OS back then. A T1 is 1.5Mb/s, and if you don't take binaries, you would not quite fill that pipe back then. These days, a $10/month VPS is not merely adequate, but luxurious for a non-binaries feed.