Wow didn't know that, it's been a while.Well then I'd say maybe 200 - 300 posts,
Some level of post-count requirement will help weed out the ones who are cruising by looking for easy pickings but going to 200 or 300 will show extreme diminishing returns, IMO. The reality is that post count doesn't guarantee anything. I participated on a forum where somebody with THOUSANDS of posts eventually scammed a bunch of people and then completely disappeared. Was a great member of the community prior to that.