The question over who should and should not be allowed to advertise things here was covered around a year ago if I remember correctly. Maybe link the posts so as we can see what was what...?
Anyway, fwiw I think the for sale section is good and should be allowed to flourish as at least it doesn't have the to$$ers that appear in Gumtree. If, however, posts are going to be modded/removed then consider having the courtesy to contact the poster first to see if any issues can be resolved rather than just kill off a post as it'll just look like censorship for no reason and that'll create it's own issues.
I've bought several things from here and so has wifey-pooh and neither of us would like to see this section become stagnant and neither, I suspect, would the vast majority of PIA users.
Just something to consider.