Something similar happened to me about 2 years ago when I was selling a tv..a woman wanted to buy it and said she would pay double what I was asking & would I post it to her son in Africa as a birthday present saying 'with love from mummy' on the parcel.
She next asked for me to accept her transfer on paypal & the funds would be sent to my account..so I accepted the transfer but the money wasn't cleared to my account.
Then I got an email from PayPal saying I needed to show proof of postage to Africa before the funds would be released.
i was very nearly going to post the tv as i was moving country & had so much to do & wanted rid of it but something made me wait.
To cut a long story short i kept getting harassing emails from this woman saying I never posted tv & she had paid me & from PayPal saying i I had violated their rules..
So I by chance googled her email address & found info of similar scams she had done before but with slightly different versions of her email address & an exact copy of her original message to me & her English was very bad too..