sometimes they hold it just for the sake of holding it

or the seller may not have the funds or they may have had a bad history or they may have gone over their payment limit or they may not be verified or a million other reasons

if he's coming to collect it, ask him to bring cash and refund the paypal

i know it leaves you in the shit for your phone but if it doens't work out, you'll be items down as well as out of pocket