Its stolen...nobody sells MBPs for $600. I would try to return it to the owner and I would also call the Police.
http://newyork.craigslist.org/mnh/sys/780309718.html Scam
http://newyork.craigslist.org/stn/ele/779903928.html Scam
Do you have the persons name?
http://newyork.craigslist.org/mnh/sys/780309718.html Scam
http://newyork.craigslist.org/stn/ele/779903928.html Scam
Do you have the persons name?