You may be able to reverse the wire if your bank wired the money, but you need to talk to your bank about it. You always should contact your local police and report being scammed or an attempted scam over the phone or by US postal mail. Also report it to the FBI here:
http://www.ic3.com
If they can't reverse the wire, you are out of luck.
Never buy anything from someone over the Internet unless you use a credit card. If it is a great deal and they do not accept credit cards, you can bet it is a scam!