Indeed, I always compare it with what I get if I ran it via cloud services and the electricity cost pales in comparison.

My NAS is around 100W (6-year old parts: i3 9100 and C246M) which comes to $25/£18 per month (electricity is expensive), but I can justify it as I use many services on the machine and it has been super reliable (running 24/7 for nearly 6 years).

I will try to see if I can build a more performant/efficient NAS from a mix of spare parts and new parts this coming month (still only Zen 3: 5950X and X570), but it is more of a fun project than a replacement.