Membership - Different for Male/Female

I finally have my site set up and as bug free as I can make it.  The last step I need to do is with memberships.  I had a mod that I thought would do what I wanted, but it is not for what I want.

What I want is for anyone who is female to have free access to the site, and for men to pay $10/month.  Does anyone have any ideas of how I can do this?

I havent seen anything like it yet. memlevels based on Sex is cool. It would be a medium level custom module. Any takers?

I would find a way of verifying their sex first, or anyone could sign up as female.  Just a thought.

Yes there is always a chance they will say they are female.  And I can deal with that issue separately.

But it does not seem like this would be a hard thing to accomplish.  Sex is part of the profile, so it seems like it could be an easy thing to write.  Anyone want to develop this?

I have a module that might work for you.  It would need to be customized to work the way you want:

http://www.boonex.com/unity/extensions/entry/Dolphin_7_Membership_Subscriptions_Module