Any seller who tries scamming like this are seriously lacking intelligence. Aside from the fact that none of these would hold up in court if it went that far, eBay is waaaay too pro-buyer for them to allow it as well. Even if a seller won an eBay dispute, a buyer could still easily claim "Item not as described" or "Item not received" and easily get their money back. As a seller myself, you can get screwed selling legit stuff, much less try and scam buyers. Hell, buyers don't even have to be truthful in filing those cases. They can literally claim any defect they want and eBay would force the seller to accept a return.
Any seller who tries scamming like this are seriously lacking intelligence. Aside from the fact that none of these would hold up in court if it went that far, eBay is waaaay too pro-buyer for them to allow it as well. Even if a seller won an eBay dispute, a buyer could still easily claim "Item not as described" or "Item not received" and easily get their money back. As a seller myself, you can get screwed selling legit stuff, much less try and scam buyers. Hell, buyers don't even have to be truthful in filing those cases. They can literally claim any defect they want and eBay would force the seller to accept a return.