and if you filled a second order and paid for it, you will have your parts in double, that is all.
It is a pain in the A to get a refund from PayPal. I am using it since 2003. It is almost impossible to cancel a payment, and IF they do, it will be after they will have done a LOT os research.
They WILL find that you placed a second order and they will tell you that you only had not to.