A friend asked me about costs etc. in running my own Mastodon (glitch-soc) instance.
My reply might be useful more broadly:
Costs: I run mine on an Intel NUC, for which I paid about ~£200. But I ran for years on a Raspberry Pi, which was fine until my account got a bit big. It consumes some electricity, and I already have an Internet connection with IPv6 and a spare IPv4. So, incrementally, beyond the cost of the hardware, very little.
Time to set up: it took me about 30 minutes *but* I am already familiar with hardening a Linux server, and I build the basic infrastructure automatically. Honestly, this is the bit that would concern me the most, for someone planning on putting a box on the Internet. But it could also be a fun learning exercise.
Time to maintain: a few minutes a month. Upgrades are easy enough. Backups are automatic (because I have automated them).