This has probably been mentioned before but I think it would be a better idea to have min post count for bidders in the Buy/Sell/Trade forums. I know it is easy for people to just post reviews to get their post count up - but at the moment I am finding it fustrating that a 1 post bidder is bidding $100's dollars for a site. Im wary of bump bidding ..
Some of my best clients have been 0 post members who lurk in this forum and do business privately. So don't judge them across the board like that. In fact most of my high budget and corporate clients through DP have had no, or very few, posts. They're too busy making real money and looking for what they specifically want to spend time posting all the time. Personally I think it's enough that they can't advertise until hitting 25 posts. Why should they not be allowed to respond to the ads of others? That seems a bit harsh. And it would be discriminatory in that they couldn't vote but they could still do business in other deals via PM. There's no good reason to treat different ad formats differently. It's also strange that someone with only 30 posts is so skeptical of new members (frankly I wouldn't consider a 30 post member any more trustworthy than a 5 post member -- it's completely irrelevant to trust in business).