paypal is retarded in every sense. even if you sold something on ebay and they used paypal to pay you its pretty easy to fuck you over.
if they pay with bank transfer through paypal its really easy for a buyer to screw over the seller. all the buyer has to do is go to the bank and tell them the seller never sent the stuff, they will sign an affidavit, they will reverse the electronic transaction and take the money from paypal no questions asked (in this type of transaction there is no investigation), paypal takes money from you the seller
if they use cc they can file a dispute against you. even if you insured the item and got tracking they could screw you. make sure they sign for it and it is their signature. if they themselves do not sign for, they can argue that they themselves never received the package and sure it might of been left on the front porch or someone signed for it but they never got it so your pretty much fucked...or they can just say the box was empty but in that case you could file an insurance claim i guess....