Read the item's description carefully. Note what it does not say .
E-mail the seller to clarify the description if necessary.
If postage and handling costs are not clearly stated by the seller, clarify this before bidding on the item. See what other bidders have had to say about the seller by carefully reading the seller's feedback. If your auction site has this function, search the seller's completed auctions. Don't get into an expensive bidding war if the seller will list an identical item next week. Include a copy of the seller's E-mail with your payment.