Our pricing is user based. For every team user, you will pay $8/month. Other team users see all your team projects and can create new projects.
If you want to invite a client or other people to a specific project, that's for free. To invite someone to a specific project, go to your project settings, click on user and add as many as you like.
If you think your team needs a discount, because your doing open source work or your team is a non-profit organization, drop us a message. We will see what we can do.