Actually, if I have a Q in regards to how I see an item being sold that can
prejudice a sale, generally only if I see/feel the seller isn't properly informing
the buyer. I always PM the seller. I think it would be rude and unacceptable
to post remarks in the thread that could prejudice a sale. However I do want
to see the seller rectify the situation too. Or I will PM every potential buyer.

However that being said I think if you have someone delibrately upsetting a
sale, Maybe think about banning them from the area for a set amount of days.

Regards,CS