- Don't purchase anything to resell without looking at the closing prices on similar auctions on line. I don't care if it is made out of solid gold and belonged to Princess Margaret. It is only worth what it will sell for and the buyers won't change just for you. Save your novelty collecting for after you are rich. If possible, go to the auction sites on your smart phone. If not possible, go home and look it up and go back or call someone with the info to look it up for you on the "completed" selling section of your favorite auction site. Think of it as insuring that you have one more latte in your world in the future.
- If you go to an auction site and some items in excellent condition are selling well and some aren't? It is almost always because the shipping is priced to high. Which is very difficult to do these days since the auction site police are strict about their pricing policies. Odds are, they are taking the most expensive, fastest high fallutin' route to post an item and folks just don't want to pony it up when things can be had cheaper. Also, sometimes the auction site will not let you post it about a certain price and you have to move, say, a very heavy book into a non-media mail category because it is simply too heavy and the auction site has a cap on $4.00 for books. Will the buyer be willing to pay for the difference? Be careful of the totals with shipping, tax and insertion fees. If you are not allowed to charge enough to cover the cost or you are posting them at a price that will not sell, you will lose money. And this is not the point of this endeavor.
- Detail your needs. This includes how you are going to package your shipping and international shipping policies or anything else that could cause consternation in the future. Look at the individual sellers with over 300 good comments in their feedback statuses and see what they include in their completed sales as far as shipping/buying policies (not the power sellers/stores...the sellers like you who have to schlepp to the post office and don't have an office set up to deal with massive amounts of sales). Then do what they do.
- Be political. Bad feedback is box office poison for auction site sellers. There will always be incidents with things like the post office destroying goods (no other business could get away with mangling a product and not apologize when delivering it), tempestuous personalities looking for a reason to get in a fight with someone (auction sites don't have a "crazy bastard/beeyach" filter ) or just a customer misunderstanding the nature of the goods. This is especially relevant when handling collectibles. Super picky folks looking for specific things in certain conditions are the bastions of unhappy purchase experiences. I have found that it is always better to swallow your pride even if the buyer is difficult and always allow them to return the item, noting that you would rather have a happy buyer than the money. It may not be true but bad feedback could lose possible future bidders. So kiss ass and return it.
- Condition condition condition. Telling every stinking detail about the item that you can pull from the recesses of the most paranoid part of your mind. Color. Weight. Demensions. The tiniest scratch or chip. The size of the tiniest scratch or chip. The name of the tiniest scratch or chip. There is no such thing as too much. Every detail is an "I told you in the item description" if there is ever a dispute. It will prevent people from bidding on your item incorrectly, taking it away from a person who does want you to keep their money.