Question about Microsoft 365 Family Deutsch

It depends.
If you deposit your credit card with Microsoft after the first year and have it debited automatically, then it costs (as of today) 109 .- / year.
But you can also buy such a key every year and enter it for renewal, then it costs as much as the key costs. So it fluctuates, but tends to be much less than with automatic renewal.

The price in subsequent years is Fr. 109.95