This is happening a lot atm... Saw another Neuron frame (Geoff Wiles, Omega built) bought for about £225 recently. Bit of bar tape and flipped for £450.
Someone could always buy it then not pay, but leave some negative feedback pointing out poor behaviour..?
That said, eBay is fairly wild west. This sort of thing is easy to police here, less so on a site that makes even more of a profit when things are flipped.
This pisses me off:
https://www.ebay.co.uk/itm/Tommasini-Sintesi-Italian-Racing-Bike-Columbus-Neuron-Campagnolo-Dura-Ace/264748897356?hash=item3da443944c:g:akQAAOSwEINe07vO
It sold, just a couple of days ago for significantly less than that.