I would go through with the sale to the first bidder, but would insure the package and require a signature for delivery - maybe even registered mail (not merely certified) so it is delivered under lock and key and there is no dispute about delivery. If the price is ridiculously high, this may be a cost you can absorb.

And if you can get payment through something other than PayPal, the buyer will have even fewer options to "reverse" the charges, but it may be too late for that now that your listing has run its course.

Another option is to contact the buyer and tell him that if he is sprelli, you would prefer to mutually cancel the transaction for "obvious reasons" and ask for reassurances about his identity.

Everything needs to be above-board - particularly since sprelli has been monitoring The Chip Board!