Chrono24 vs EBay am I being scammed ?

[Timpointoh]

So I just bought a watch off of Chrono24 From a private seller

Now the seller is reaching out to me, asking me to Cancel on chrono and buy on eBay

Everything he said initially was how it benefits me, but I’m like why are you offering this? Why do you care? And this is what he said:

“The benefit for me is that I get to send it to eBay authentication service and then they send it to you. So eBay confirms that I shipped an authentic watch then you receive it. If you want to return, you have to return the same watch with the tag on it plus authentication card. for me it protects me as a buyer that what I send will have to be sent back if there’s a return or issue. Chrono just has a lot of scams )not saying that you are)

it will just make the transaction safe and insured for both of us. Byron and seller can’t scam or send fake.”