There is only one registration/user type available in ClassiPress by default, so whilst you can offer free or paid ad listings, it's not determined by the type of user as you have indicated. There is also no cart functionality available within the theme, however you can set up membership packages which allows unlimited ads for a set price. Anything outside of this default functionality would require customization on your part, but as our themes are not encrypted, you are free to make modifications if you wish. Thanks.