There is only one real way to always be safe when purchasing an item on ebay. You have to use a credit card either directly with the seller or through paypal. With a credit card, VISA, MasterCard, Discover, AMEX and PayPal will back the purchase 100% if the seller is a crook. If you use a money order, cashiers check, personal check or cash you have no protection. If you use a debit card you may or may not have protection. That is up to the issuing bank and you need to check with them directly.

There are time limits on your protection however. With credit cards it is 90 days and with paypal it is 45 days. So do not wait to file a complaint if you feel you are being taken advantage of.

• With the credit card companies, call the toll free number on the back of the card and ask to dispute a charge. They will ask for information as to why you feel the service and/or product was not provided and take some information. They do require that you have written proof such as emails or faxes that you have attempted to resolve the issue with the seller. You must also give the seller the opportunity to make good in a reasonable time frame (2 weeks max is industry standard).  Keep in mind that if the seller is communication with you and is attempting to assist you even if you don't like what they say, you must according to credit card rules at least give them the opportunity to make you happy. They may not be able to and at that point you proceed with the credit card company dispute. Keep everything in writing by email or fax. Phone calls mean nothing to a credit card company, a bank, paypal or ebay as they can not be verified. It may make you feel better to call and yell at a seller but it is only here say and means little if anything in a dispute situation.
• If you purchase an item and pay for it with a credit card, by regulation, the part has to be delivered to you within 30 calender days unless you have agreed in writing with the seller that a later delivery date is OK.
• A seller as the right to demand shipment be made only to the billing address of the credit card or to an alternate registered address. If you can not or will not provide such an address they are not required to ship your order but do have to refund it in full. You can add alternate shipping addresses to your card by calling the toll free number on the back of your card and asking your card issuer to do so. Most will allow up to 6 addresses for you to have on your card.
• If a seller ships an item to your requested address and you for some reason can not accept the item and it goes back to the seller, you are responsible for the shipping fees. This includes if you make an error in the address you provide.
• A seller can not charge you a restocking fee on a part that has not shipped. This rule does not apply to special order deposits which can be non refundable but must be listed as a "non refundable deposit"
• A seller does not have to refund an order that was damaged in transit if you did not pay for insurance unless they stated it was included in the shipping & handling fee.

The most import way to protect yourself is to never buy an item with cash, checks or money orders. Unless you have good vibes and it is a highly rated long term seller that you think is going to be around for a while always use a credit card. Then you always have protection from the credit card company.