There isn't, but there's also the situation that we have in Buy & sell to consider - if someone turns up out of the blue and advertises, the advert is deleted. Rightly so. But what about if a long standing, helpful member posts something for sale (or that they want) and the person who replies has just turned up out of the blue? To delete them loses our helpful member a sale. It's never going to be perfect but I really feel strongly that twenty quid will discourage the users. If puppies are offered free everybody wants one
I remember one company (maybe all companies) that do long term rentals charge a month's rent to the buyer and a month's rent to the seller - people say us real estate people take too much, but the easy cash on rentals - with no more responsibility than putting a renter and owner in touch is outrageous. Once again, the CB forum is compulsive, not compulsory - if people prefer to use agents then that is their choice
My only personal negative about this is that it will mean that chancers will cause us to delete their efforts, giving further impression that I am a miserable old git, which I am not!