I think it is important to also include hardware in this group, as hardware for selfhosting is different, both from user PCs as they are discussed elsewhere, and from large, professional hosting hardware, which is usually outside the range of selfhosters.

I support striking that part from rule 3.

There are companies dealing with used and refurbished hardware. There are loads of PCs around that are not bloated enough for Win11, but still make good home servers. Depending on specs and prices, buy more than one for extra RAM, a second SSD, and spare parts.