That also sounds exactly the kind of action that a normal person would take to sell a GPU he no longer needed.

Not really. I would never begin an ebay account with selling. I would start with buying, get some positive feedback and completed transactions before moving on to selling small items initially.

As a buyer, I would never buy anything worth hundreds of dollars like a GPU from someone with zero feedback who just joined ebay.

Well, in case it works that way - they better create a tutorial and block the features for new users instead of insta-banning.

What kind of fraud? There is buyer protection and zero risks for eBay - PayPal won't release the money until the delivery is confirmed, what you are talking about?