Maximum storage on Apple One is 4 TB (+5 GB)

[nutmac]

From Apple One product page:

What if I need more iCloud storage?


You can purchase additional iCloud storage separately to supplement what’s included with your Apple One plan

At first, I thought I can pay the different to upgrade to the next tier (e.g., pay $7 more to upgrade Apple One Family with 200GB to 2TB). But I was wrong. You buy supplemental storage for up to 4 TB maximum storage.

Apple One Individual with 50 GB iCloud:

• $14.95: 55 GB total = 5 GB (free) + 50 GB
• $15.94: 105 GB total = 55 GB + 50 GB
• $17.94: 255 GB total = 55 GB + 200 GB
• $24.94: 2,103 GB total = 55 GB + 2,048 GB

Apple One Family with 200 GB iCloud:

• $19.95: 205 GB total = 5 GB (free) + 200 GB
• $20.94: 255 GB total = 205 GB + 50 GB
• $22.94: 405 GB total = 205 GB + 200 GB
• $29.94: 2,253 GB total = 205 GB + 2,048 GB

Apple One Premier with 2 TB iCloud:

• $29.95: 2,053 GB total = 5 GB (free) + 2,048 GB
• $30.94: 2,103 GB total = 2,053 GB + 50 GB
• $32.94: 2,253 GB total = 2,053 GB + 200 GB
• $39.94: 4,101 GB total = 2,053 GB + 2,048 GB

Hopefully, non-Apple One iCloud customers would be allowed to purchase supplemental storage as well. I have 2 TB and I would love to pay $9.99 more for 4 TB total.