Hi,
You can set condition to add/remove user from usergroups based on a field value. Easy Profile does not handle payments or subscriptions, so to change value of fields or usergroups after some payment you need use some subscription component and check its features.

Many subscription components have these feature:
- SQL query (if subscriptio component not have a plugin for Easy Profile, you can simply change the value of some field with a query)
- Add/remove Usergroup