The Internal Revenue Service has denied 501(c)(3) charitable exemption to cooperative art galleries that exhibit and sell their members’ work throughout the year.  It has taken the position that such a gallery is operated primarily for the benefit of the members and not the general public.  I think your single annual fundraising event is readily distinguishable, and, while the IRS might take note, these sales alone should not suggest that the Society is conducted primarily for the economic benefit of your members.

I am actually more concerned with your statement that you provide education “to our members and other clubs who request our service.”  I would have expected you to say that you provide education for your members and the general public, and that you have some specific means to let the public know of the availability of your information.  In addition, when you talk about “other clubs,” you are associating yourself, perhaps unintentionally, with a separate non-charitable class of social clubs exempt under section 501(c)(7).  You will need to convince the IRS that your program is broadly educational for a whole lot of people, and not primarily a social activity for a limited number of members.