Hi mobile-phones-etc
As you may be knowing, we believe most "People are Good"
Sellers doing something like you mentioned in your example is possible, but rare. We would not want to restrict business due to some bad apples. We would rather deal with unscrupulous elements separately without troubling everyone else.
However, in any genuine damage, I will have to repeat what I have said earlier. Courier companies have limited liabilities towards lost or damage in transit. On a case-to-case basis, eBay will attempt to resolve claims for loss /damage in transit between the seller and the concerned courier company