Current planned use cases are Pi Hole, Bitwarden (password manager) server, probably general network storage and torrenting, whatever other "homelab" things I think of later (which is why the specs probably seem a bit overkill)
Lenovo ThinkCentre mini desktop, eBay refurbished, $184 before tax
8GB RAM, 500GB SSD
Intel Core i5 6th Gen. (they don't specify but I'm assuming it's a 6000 series, which was released in 2016)
Direct link to the listing: https://www.ebay.com/itm/293526962748
well for anyone curious I wound up getting this: https://www.ebay.com/itm/195795479442
much lower price, newer CPU (8th gen i5 instead of 6th gen), same amount of RAM, same storage but HDD instead of SSD
I'm probably going to start out using it as is but eventually upgrade the storage to a 1TB SSD and maybe at that point a 16GB RAM kit will be less than $30