If they find someone to pay $15,900 then good for them: not so good for the buyer.
It’s a pretty safe assumption that any special that you buy complete will not give you reliable transport, so what are you buying? If you want a project that you will spend time and money on, making it reliable, you can get one for a small fraction of $15,900.
They list loads of expensive parts that are in the bike. OK, but you can’t get the new price back for those parts.