It turns out I could have renewed by buying the $83 family pack.
I'm going to see if I can get a refund. Don't make my mistake!
Update 10/20/10: I had a very satisfactory response through Apple's Express Lane. I have 45 days after payment to cancel for a full refund. If I then reactivate with a family pack key I get all the family accounts and data back -- Apple keeps it for a time (forever?).
So I'll order the renewal package from Amazon. When I have they key ready I'll cancel for the full refund, then immediately renew using the Amazon family pack key.
Update 10/28/10: This worked, with only a few surprises. Here's how to do it.
- Before you cancel, make sure you have every family members user name and password at hand.
- Cancel the account for a full refund (within 30 days).
- login again with the account owner un/pw. You get a note that the account has expired. Enter the MobileMe key you got from Amazon.
- You will see your account, but nothing about family members!
- Now add each family member back, one at at time. When the dialog comes up it will ask you if you want a new account or to migrate an existing account for a regular member. I chose the 2nd option. Enter the un/pw of the family member. It takes about 30 seconds for the accept button to appear if you've entered correctly. Errors get an immediate response.
As best as I can tell no data was lost. I could see all the synchronized contacts I expected to see.