oh hey! It was $670 australian dollars, with no ram, no hdd, no wifi. so bare bones. this was back in October 2021. It’s now a fair bit cheaper. This is the aliexpress link if interested. https://www.aliexpress.com/item/1005003331392517.html?spm=a2g0s.12269583.0.0.60c06558Sa8ykB
as a newcomer to all things federated (I skipped mastodon as I never used twitter), the best piece of advice I have is to not overthink the whole federation idea. Just sign up with an instance or two (I signed up to kbin.social and lemmy.world). See which instance format suits you best. You will (should) be able to interact with all other communities/magazines etc. I started off liking the interface of kbin more, but find myself using lemmy.world. Just start searching for communities, find ones with decent userbases and start interacting. Feel free to down this to oblivion if I have the wrong take on this!