my first advice is always pay with VISA or MC. Unless you know the person. As far as the money order tracking goes, that will help you find where he cashed it or deposited it, which will give a starting point to locate him. See if you can track the MO, then you would have to hire a detective to find him. Considering the costs and energy involved (if you have the resources to do locate him go for it) I would let it go.