If you ever get emails which seem like they are from ebay or paypal and they are asking you to enter your password or credit card details then don't do it!
If you are in doubt as to whether an email is from ebay or from paypal then just forward them either to spoof@ebay.com or spoof@paypal.com. They will then send you an email back saying they will investigate, they will later send you another email which normally confirms the emails were not sent by ebay or paypal.
If you do get carried away and enter your credit card details then phone your bank immediately to stop your card. Also email ebay or paypal to tell them what you have done. Also change your ebay or paypal passwords immediately!