Atlassian provides free licenses for non-profit organizations (further information). If you have such a license we'll give you a free license for the User Profile Plugin. Please mail us at mailto:confluence-support@communardo.de with the following information:

• a proof that Atlassian accepted you as a non-profit organization
• the Server ID of your Confluence
• the version of your Confluence
• the number of users your Confluence is licensed for

Similar to Atlassians rules this applies also for Open Source Projects and Classrooms. Qualified academic institutions receive a 50% discount on licenses.