i think the for sale section on this site is good, least people can see members previous posts and topics, where as you cant on the likes of gumtree and preloved..
just think if you was a newbie wanting to get a dog where would you start if you had no friends in the sport , i know id rather be looking on here than on some selling site
i think being a donator and having a minimum of 100 decent posts should be the criteria before your allowed to sell in any of the sections