It’s really not that complicated. At a high level:
- $5/mo for having the service turned on
- $5/mo for every TB storage above and beyond the first 1TB
- $1 for every TB of data transfer beyond the first 1TB in a month
And then divide those numbers because it’s actually billed by the hour
To be fair it’s power consumption is effectively zero at standby and only 4-5W at idle/light usage.
If you were worried about this amount of power usage you would be better off unplugging your microwave when not in use to avoid running the clock display