Posting Rules promote lots of garbage

I get quite frustrated with the posting restrictions for people like myself who are here to learn, and haven't got a lot to say that would be of much use to the learned elite.
When I buy from the WSO, where there are often vey interesting offers, I am not allowed to post a question about the offer, even if I have already purchased and need help.
I am also not allowed to PM the seller.
When I have a serious comment for a thread that I think is relevant and useful - then I will make a post, but if I keep my posts to the relevant and useful, it will probably be quite a while before I reach the magic number of 30.
I guess that explains why so many threads are full of filler posts from members with post counts in single digits.
Posting just to increase ones post count can not be good for the forum, and brings to mind the analogy that one has to plant a certain number of weeds in the garden before being allowed to plant flowers??

Now the million dollar question. How do I contact a member that I have bought a WSO from for help when I have less than 15 posts?

Ed