He uses 3 products: Proton Mail, Proton Pass, and Standard Notes.
Here are the pricing per year:
Proton Mail Plus: $47.88
Proton Pass Plus: $35.88
Standard Notes: $90
The total amount he currently pays per year: $173.76
Your suggestion:
Proton Unlimited: $119.88
Standard Notes: $90
The total amount: $209.88
The answer is to save $209.88 - $173.76 = $36.12 per year.
He does not have the need to use all the features in the Unlimited plan. And the Unlimited plan does not include Standard Note, which is something he wants to use.