Nothing turns people away from an auction site more than dealers that appear that they don't know what they are doing. This can be from different reasons.
One thing that I hate is over inflated prices. I have seen many stores where the asking prices are much, much more than the products are really worth. If a customer happens to stumble upon this store, would they continue to look at different stores?
I myself would not. It makes the whole site that hosts everyones store look less legit.
Another thing I have noticed is that many auctions have incomplete discriptions. Answer everything that the customer may ask in the description. If you can't answer something, do the research to find out. Ask yourselves, would you buy this item with the description. I know that some items are truly unique and may be difficult to reasearch, but at least try.
STAND BEHIND YOUR PRODUCT 100%, SHOW CONFIDENCE AND KNOWELDGE IN YOUR PRODUCT. TRUST IS THE KEY TO SALES!