was it a flat rate box for both packages or your own packaging? I would give it a few more days.
USPS seems to be super fast and reliable when shipping with their flat rate boxes, but if I do my own packaging it is always slow.
it means if you ask a 100 different usps agents the same thing one of them is bound to give you an answer you like.
basically bug the hell out of them till they give you what you want.
well you pretty much screwed unless he helps you out. He seems to have been online recently, has he answered any of your PM's?
Honestly I think you waited way to long, how did you let 3 months go by before do anything ?
have you escalate the dispute to a claim yet? most likely if he is scamming you he would have taken the money out of his account already. hopefully paypal make it right for you.