So, I started playing with the concept. It would be reasonably straightforward to add a contract package that has no active account, until someone else comes to claim it.
I am however not too excited about the idea of *anyone* being able to sign up to the website and take that account. There needs to be some type of vetting in place.
How about a system where users who are not ready/willing/able to pay can ask for a spot from those who have a group subscription?