Is it possible to upgrade only one account on a single Google Apps domain to the Unlimited (or 1TB since I have less than 5 users), $10/mo plan while keeping the other accounts (same domain) on the free version? I'm running out of space with my 25GB on Drive and would like to have 1TB but don't want to pay for the other users to have 1TB when they don't even use it.
If that's not an option, is it possible to keep 1-2 users as the $5/mo plan while having mine at the $10/mo?
Also, would I be able to downgrade from the $10/mo plan to the free plan?