We're technically sharing space, but each of us has an upload limit of 15gigs (for a freemium google account).

Basically, we're sharing small pieces of our own Drives, with my Collab Folder acting as the poster boy for everyone. So even if you created a new folder and people starting dumping files in there, there's no impact on your own storage limit, just on each individual person that contributed.

Since we have about 15 people involved, that gives us at least a collective minimum of 75gbytes of storage.