I dont agree with this idea Cem. Upgrading is a better feeling than beeing downgraded. The Standard level in my opinion is a good starting point for every new user / profile. No matter if its a persons or an orgs one.

To adjust this Standard level to the basic needs of a site is easy. Then you can setup one premium or different paid levels for upgrading, step by step. So the user knows exactly what he/she is paying for.