I saw this thread while I was currently in the process of selling my ps4 on ebay, prompted me me to take a snap of the serial, so no matter what happens OP, this thread has done some good by getting helpful info out there.
Maybe I've just been really lucky with ebay over the years. Only problem I've had is with a western digital green hdd I sold, guy claimed it wasn't 7200rpm, which the amazon listing template must have said, ended up having to send him almost half the money to appease him.
I've also had non-payers before, but I always go through 'unpaid item process' instead of immediately relisting to and make sure their account is marked for an unpaid item.
I've sold all my consoles, various old PC parts, various hifi equiment, and never heard a peep from anyone really.
My advise is to put a number of bullet points at the end of your listings, things like
'check feedback and bid with confidence'
'no time wasters, only bid if you are interested'
'if you have less than 20 feedback message me before bidding,'
'all products are fully inspected and photographed before sending'
None of that really means much, but a scammer is perhaps less likely to pick your item if he sees those red flags?