Originally posted by jogiba And if the USPS loses it your out $320.
If you have the package scanned when you drop it off at the post office, then I don't think you'd have much to worry about regardless of what happens after. If QVC claims they didn't get the camera back, and you can show that you sent it via return label method they provided you, I have no doubt your credit card company would side with you in a dispute (assuming of course you paid with a credit card).
That said, the actual chances of the package getting lost when using a prepaid label that is properly attached to the package is exceeding small (<1%). The majority of lost mail results from poorly attached labels and or handwritten labels that are illegible. Personally I've shipped and receieved well over 300 packages via USPS over the past 2 years and not a single one has been lost. One package last year was significantly delayed due to an error on their part, but even that one eventually was "found" (they marked it in their system as "delivered", when in fact it was sitting in the post office waiting to be picked up).