I paid him $30.
He received the payment, confirmed that he received it and after that deleted the entire conversation and blocked me.
Most of the cases it's normal when you will go to trade with a newbie account here. You should use escrow to make this deal. Though it was very little amount but somebody could help you to make the deal smooth.
Better to learn from here and use it from the next time. And better to not make deal with a new account here.