I see this a couple ways. A guy that uses a single or multiple free accounts to sell should be criticized for not making an honor payment. He is abusing a privelage.
An individual who pays a membership fee should not be called out here. They have paid for a service and are using it. If those at RJ think the income is not enough from memberships, then they need to adjust membership fees accordingly.
I pay to list pieces parts here and my cars occasionally. I also have several other places that I post for free. If or when I sell something thru RJ I try to make an honor payment. As you can see, I have made a couple. The couple I have made have been far more then the required or suggest amount of the sale. Most of the stuff I have sold has been thru other sites or locally. It makes it hard to determine where and when stuff sold if the buyer does not report the item as sold. You can't assume that just because ads come and go that the item was sold on RJ.