Since joining Internations I have made a conscious never to attend an event where I am financially penalized, because of my sex. Where I have worked before the women made 14K more than I did and had no experience in teaching. They also got two months paid leave while I received 2 weeks. I refuse to support or give my money to an organization punishes me for being a male.
Seriously, have you tried hosting an event where men and women are charged the same? I guarantee you the turn out of women won't be any different.