Affiliating your group with the SSA and getting access to our affiliate services is free. The primary task of the SSA is to support atheist/humanist/freethought/skeptic groups on high school and college campuses.
Joining as an individual member is $10/year for students, $25/year for educators and $35/year for other non-students. The SSA is a democratic membership organization and these members not only elect our board of directors but also provide a significant amount of the money that lets SSA support affiliate groups.