- you will not send first,
- you using paypal payment (high risk chargeback, dispute) but you not send first.
That's very high risk and 2 times risk for bitcoin owner (because payment can't be reversed, it can't chargeback).
just suggestion, you must have others payment method.
How is that? If you send it as a gift, there's no way to charge it back. Plus if you put both wallet id's in the description and point to the transaction on the blockchain, it should be fairly easy to see that the transaction occurred. Just a matter of getting a competent paypal person in case of a dispute