I always find it slightly amusing when I see a listing on eBay where the seller "offers" tracking and/or insurance for an added fee, warning the buyer that it's a good idea to protect themselves from lost or damaged packages and how they aren't responsible if anything goes wrong if the buyer opts out of it.
In some cases, with small-time or infrequent sellers, I imagine it's simple due to ignorance on their part.
But with the larger sellers, who certainly know what the policies are, it's clearly a case of them trying to trick (or one might even say defraud) the buyers.
The fact is, the seller assumes total liability for the item until it arrives and is signed for and accepted by the buyer. Not only is this the policy with eBay/PayPal, but it's a standard practice of doing business. If you don't receive something, or it arrives damaged, it's not the buyers fault and they aren't liable for the cost. Even their credit card company would support a dispute.
If I'm not mistaken, I believe I read something on eBay's website where it prohibits this type of trick too.