It really isnt bad. I do most of my computer at home so I really only need a small cloud box to pipe things through when needed.
And I could reduce the B2 price a lot with some deduping of my data, but that’s an ongoing and painfully slow process since I was too reckless with my local backups in the past, so $7 to avoid that process is worth it.
And for electric I suspect it’s pretty low. I’m running 3 raspberry pi, a 4 bay NAS, and one micro PC and I live in an area with pretty cheap electric already. I think my gaming machine probably takes more power in a few hours than the rest of the system does in a day.
Many registrars let you buy a domain and set up dynamic DNS for it within their system so you can own a domain and get dyndns on it.
Otherwise you could accomplish it with a VPS but you’d only need the smallest one available because it would just need to run nginx to forward to your home ip (and a small tool to update that IP when it changes). So you could probably get something for less than $5/mo.