1. You're on your own. The SD Company takes no responsibility on any trade from this site.
2. Communicate with your buyer or seller. Good communications goes a long way to keep misunderstandings from happening.
3. You should only respond to a Trade Post in a positive manner. If you don't have something nice to say, do not post. Do not comment on someone's selling price. Quoting a price from somewhere else is considered bad form and shows a lack of manners.
4. If you wish to make an offer to someone, do so privately.
5. Asking people to make offers doesn't lead to too many sales. You'll be far more successful if you figure out how much you want for something and just post the price. This is nothing but a suggestion. You are welcome to sell in any manner you wish.