Sounds fishy. Personally, I'd never use PayPal for that kind of deals because PayPal always protects the buyer, never the seller. I know several cases of frauds where someone sent a perfectly ok product, and the scumbag buyer claimed he didn't get it or the product was damaged, then got paid back by PayPal and additionally the legit seller (who didn't do anything wrong at all) got his account frozen and lost his guitar/studio gear and all money on the paypal account.
Just request him to pay by bank transfer (no cheque!) that way the payment can't be called off so you have the money guaranteed, or let the courier give you the money in cash (again, no cheques or PayPal for people you don't know).
That's just my personal opinion though and only counts for people I do not know at all.