I totally agree with this.
I understand that having a well used classified section benefits the forum as a whole.
However, having a reputation as a decent place to buy stuff, from regular members, with some form of track record would be better in the long run.
I'm a member of forums for other hobbies and generally the for sales section is behind a "wall".
And to get past it, you have to have been a member for x long, with a post count of x many.
It means that to get to the sales, you have to be engaged with the forum.
And the advantage of that is that people end up staying well beyond their need to sell y or buy z.....
I'm not suggesting that we put the classifieds behind a wall - but making peeps work a little for the privilege of being allowed to post sales is definitely worth thinking about imho.