It really depends on which services you need besides whatever hardware you have lying around.

For me it's a bit higher, as I used to host all my stuff on a rented dedicated box. Having an always on server in my bedroom didn't work for me, I have moved out since and built a local sever.

• Dedicated Hetzner server + 10TB storage box: ~75€/month
• Netcup VPS (external monitoring): ~6.50€/month
• Kavita+ subscription for additional features: 5 USD/month (I think)
• Various domains: not sure, I have ~7 domains so another ~100€/year
• Mail: 90USD/year
• VPN: ~50USD/year (forgot to track this expense, oops)
• Backblaze B2: ~2€/month

If you only need a public IP to reach your stuff, an even cheaper VPS should suffice.

Edit: forgot some stuff in the first pass