JohnyMac, it's not about being a part of a club. It's about preserving the integrity of the site. Several other forums I've visited or in which I've become a member do the same thing. It prevents the spamming of sales onto the forum. You don't see the problem now because we're not very well known. However, that's the perfect time to figure it out. When we DO feel ready to take the next step and really starting increasing member numbers, the people who don't contribute to the community in a positive way but still want to sell their stuff (which can really just be junk or non-prepping related) will become a problem. Thinking long-term, this is a necessary and uncomplicated solution to preempt this kind of behavior.
Also, you really need to set it higher than 10 posts. You want to make it so that the number of posts isn't ridiculous, but also make it so that it is very difficult to spam the mandatory post number without it being noticed by the moderators and other members, who would take action against it. 30-50 posts sounds good to me. That will guarantee that the poster must contribute some positive things to the forum or risk facing disciplinary measures by moderators.