don't have an old pc lying around? I literally built my first server while I was jobless, (I did purchase HDDs when I was employed, though). That same server has a cpu, mobo, ram and case that are well over 15 years old now, only the PSU and storage are new.
I'm hosting a discord alternative called sharkord. Initially I just hosted it on my home server, but I couldn't open ports for voice chat so I did move to a VPS with akami (linode). At most it's costing me $5 CAD a month.
It's wayyy lighter to run compared to lemmy, because servers aren't federated. I know, different application, but just wanted to provide a point of reference.
oh yeah, and I don't know, but I only run linux, and almost never shutdown my main PC anyways, only reboot for updates or shutdown for maintenance. I could 100% just host things on my main PC, but it's only connected to the internet via wi-fi, which is why I went the separate pc route. If you need parts, see what people are willing to give away.