My interests line up pretty well with my admin. I think that the instance should be pretty reliable as long as I want to keep using Lemmy.

Well you can get a domain with a weird TLD for $2-5 a year and $40-80 once for a SBC like a raspberry pi to run it. Ideally you’d want a small 32-64gb ~$20 SSD or HDD for storage, but in a pinch a USB stick or micro SD card that you can get for ~$5 would do. Any old computer can handle it though, Lemmy is pretty lightweight, you would have resources left over on the host to run other services. So in total if you wind up in over $100 something went wrong somewhere.

For what it’s worth, once you get to the single user level, the cost is pretty much nil assuming you have the hardware and domain already

This is a big part on why I think self hosting is the way to go with federated platforms. At least I probably shouldn’t ever have an issue with the admins/moderators at lemmy.teuto.icu. Being able to just point the domain name somewhere else should make migrating as simple as spinning up a new container too.