How do I create a PRO site site without charging a fee?

Is there a way to take advantage of prosites control of services without charging?

We are setting up a WP Multisite store and wish to give users free access to create blogs but still control what MS services they can consume.

As far we we can see we cannot assign certain PRO functions to the built in "free" level... if we create any other level that we CAN assign PRO functions to, we have to conduct a transaction (charge a fee) to successfully assign a higher level beyond free.