Audiogon is becoming the hub for scammers.

Um, that would be peace of mind...

I saw a 452, but when I saw the price, it seemed quite obvious...same with a recent Anthem STR...

It’s the responsibility of the manufacturer. 
Before you allow your blood pressure to rise from my comment please allow me to explain.

When you purchase a Ferrari, either new or vintage, the owner is entered in a registry so every owner is verifiable. The registry also contains maintenance and provenance data. Enter the VIN on the registry and every single detail of the car appears. If the last address doesn’t meet or match the current owner then you can be suspicious.

Pass Labs does this, McIntosh I’m not sure.

let say father is audiophile and his teenager son wants new iphone with beats headphones,he takes pictures with his android phone and sells his mcintosh gear,but ships nothing:)) I had similar experience when I wanted buy krell fbi amp,googled name of the seller and it appeared to be young guy abaut 15-17years old on facebook:))

on ebay a lot of scammers on other sites also

The INTERNET  has been,  IS,  and will always be the hub for scammers.

BUYER BEWARE!