Edited June 25, 2021
at 01:12 PM
This is $40 off PER YEAR via an Amazon subscription to Microsoft 365 Family.
I have tracked offers on Microsoft Office (now Microsoft 365) subscriptions for several years, and this is the best offer that I have seen on the "family" version (6 people). It is $59.99 per year, with subscription through Amazon. This part is key: the implication on the Amazon page (top, right column, under "Add to Cart") is that the renewal price stays the same each year:
"Your subscription continues until cancelled. If you do not wish to continue for $59.99/year plus any applicable taxes, you may cancel anytime by visiting your Digital Software Subscription Asset Manager from Your Memberships & Subscriptions under Your Account."
Note that the offer is "Deal of the Day," so only good for today. If you want the best, perpetual deal on Microsoft 365 Family, I think this is as good as we are likely to see.