If the item fails to arrive or if it is not as described, you can file a claim with Paypal.
The seller can then correct the situation or refund you. (If he is overseas, go for the refund.) If he does neither, PP will refund you and go after him. You then leave feedback and Detailed Seller Ratings.
We sellers need Delivery Confirmation to avoid fake claims of non-delivery. We pay for insurance as part of our sub-contract with the postal system for secure delivery. Neither provides any benefit to the buyer, which is why eBay requires the seller to include such costs in the advertised shipping cost.