I think as the moderator, you should stay out of it and not get in the middle of a dispute between buyers and sellers. This isn’t eBay. I think you should consider a review process similar to OfferUp. When a seller marks an item as sold, an instant request for a review pops up, allowing the buyer and seller to leave a star rating. That would be a much better way to handle these situations and give users a way to hold each other accountable. If the item doesn’t sell because of lack of communication , or a no-show, maybe the same rating system can be applied. This could be accessed if the seller or buyer chooses “ sold pending funds” before the meet up. If it doesn’t work out, then the seller or buyer will unselect SPF, the same rating system will pop up asking as to why it didn’t work out. Both the seller and the buyer can say the good, bad, and the ugly if they choose to. Just my $.02.