First off, Ubercart rocks! Many thanks to the team for an excellent Drupal module.

Secondly, please pardon me in advance for a long posting!

We are trying to set up a website that allows new users to:

1. create a basic account (this is free)
2. enroll in our school by paying an Enrollment Fee
3. register for classes they wish to take (each class is also fee-based)

Account creation works fine. We have the Enrollment Fee and each class set up as items - users can browse the catalog, select items, etc. That all works just fine.

Here's what we want to do (our design):

4. When a new user just has a free account, their role is set to "student_new_account".

5. When a user has the enrollment fee in their cart, their role is changed to "student_enrolled" (note they've not yet paid, but we want them to be able to enroll and add courses in one financial transaction).

6. If a user just pays for the enrollment fee only, their role remains "student_enrolled"

7. If a user pays for the enrollment fee and for at least one class, their role is changed to "student_registered"

My questions are as follows:

8. Is there a way to implement a role change based cart contents? (see #5 above)

9. Is there a way to prevent a new user from removing the Enrollment Fee from the cart if their role is "student_new_account"?

10. Allow a user to browse the catalog any time, but prevent a user from registering for a class (or even adding it to their cart) if their role is "student_new_account" (i.e., until they've paid the enrollment fee they can't register for classes)?

11. Finally, prevent a user from adding the Enrollment Fee into their cart if their role is NOT "student_new_account" (this prevents them from paying the Enrollment Fee more than once.

Thanks to anyone who has read this far into the posting and might have some ideas on how we can implement this!