I don't get the logic of selling you any alt for -10% market price. If anyone needed to sell any alt then they'd rather sell it at the exchange and get full market price. :/
The only way people will use this service is when a person cannot register in any exchange or if they are selling a dead alt which no one wants to by but you'll buy.
He already got scammed out of his money

not surprising at all really. I feel like one of us should have warned him that nobody will actually do this deal unless they are trying to scam.