Yes it is a common scam, do not contact them again, do not send anything, report the account to ebay for false contact details and possibly as a hi-jacked account.

Be very careful over the coming months that you do not fall for any phishing emails, that is what these scammers are interested in, harvesting email accounts, if somebody actually sends them something then that is a bonus.

If you did fall for it the next thing that would happen is you would receive what looks like a genuine Paypal email saying the funds were available and would be released on proof of shipping, of course once you sent it and contacted Paypal they wouldn't have a clue what you were talking about!