I don't think increasing the post count, or asking for a very long membership term, for posting ads will improve anything. Dishonest, or just greedy people will always exist and they'll have the patience or the workarounds to be here and trying their tricks.
I contacted Lucky_star some days ago for a pair of HP-2 he had for sale. He was asking a high price, way over the price I saw a similar pair sold a few days before. Now I'm sure he had purchased Laurent's pair and was trying to sell it for a big profit. He tried to push a quick sale by talking about a supposed buyer who had offered even a higher price. I decided to pass, moreover he said he had sold them, but it was a lie since the cans are again for sale. Then he offered to me the HP-1 he's also selling. I asked for a few days to make my mind up and to expect the outcome of other deal I was considering. He seemed to agree but before that term passed, he posted his for sale ad. That's a lame attitude which created a lot of suspicion and that made me staying away from this guy.
I don't think it's a crime trying to buy things for a low price and selling them for a profit, it's how this market economy works, but I dislike people using the friendship and good vibes at this site to do so. The only thing I find questionable in the least is his using two different identities to buy and to sale gear. IMHO if that goes against HF rules, both his identities should be banned and his IP filtered.
Rgrds