Thanks for the reply. The only slight confirmation I'm looking for is that even if I'm the family Organizer, someone else can turn on sharing, not just me, and I don't have to opt in. It seems reasonable, but I'm still basically paying the bill for all the plans while I stay off the family shared storage.
I'd love to consider Apple One as an option, but no one in my family uses Apple Music, and the added cost just isn't worth it to bundle in a service none of us need.
Right now, we pay for a 2TB plan, two 200GB plans, and a 50GB plan along with Apple TV (totally $23.95/mo at current prices). If I start sharing my 2TB plan for now and we all share it, that drops us to $16.98/mo for a 2TB plan and Apple TV (compared to 32.95 for a 2TB Family Apple One plan with lots of other services added that we don't find necessary right now).
If, in the future, we decide we need more data, I plan to stop sharing my storage, go back to my individual 2TB plan, have my wife add a 2TB plan to her account, and have her share that with the family. That would bring our total to $26.97 and we'd effectively be using 4TB of data (though my 2TB would not be shared). This is the root of my question -- wanting to make sure I could do that.
That same total storage with Apple One would cost (if I understand the pricing right with added storage -- which is hard to find, by the way) $42.94: $32.95 for the Premier Family plan + $9.95 for an additional 2TB of storage. I understand that it would include a lot more services (which we currently don't find necessary) and that the 4TB would, I believe, be shared by all. Nonetheless, that adds nearly $16/mo compared to the $26.97 noted above. Now, if Apple would let you increase your storage for less (e.g., $4.99/mo to go from 2TB to 4TB on a shared plan) that would help some, but only some.
Any thoughts or comments are welcome!