As a seller, your number one goal is to make money.   First, you need to sell items that people want or need.   Selling price will depend on supply and demand.  If many sellers are trying to sell the same item and there is low demand, the advantage goes to sellers with the best combination of price and customer service. 

Here are some general,  helpful guidelines for sellers.:

1. Provide detailed and accurate item description.  Include a clear image of your item.

2. Charge fair Shipping and Handling fees (or you STAR Feedback Rating will suffer).

3. If practical, offer international shipping.

4. Accept Paypal, money orders, and personal checks.

5. Use MY MESSAGES to let buyer know that payment arrived.

6. When payment clears, ship out the item and leave positive feedback for your buyer.

7. Use delivery confirmation (and insurance for items over $250).

8. Try to ship out items as soon as possible (or you STAR Feedback Rating will suffer).

9. Look at things from the customers' point-of-view.

10. Offer a full-refund (including S+H), no-questions-asked, money back guarantee.

11. Understand, that the occasional refund is part of ''The Cost of Doing Business.''

12. Avoid leaving negative comments and arguing with your customers. Just live and learn, and move on.  If someone does leave you an undeserved neutral or negative feedback, add that userid to your Blocked Bidders List.

13. Following these guidelines should keep your overall Feedback Star Rating at 4.8+ and your overall eBay Feedback at 99.9%+   These help draw more customers to your items, which means more $$$$ for you - and that's the goal, right?