It may sound crooked but it protects the buyer as well as myself. When I ship a bow I put a detailed bill of sale in the package to establish value along with a "care and feeding guide for the bow", all very professional looking. On the bill of sale I give detailed specifications for the bow, mark it "paid in full" and a hand written "thank you for your payment". I also add the cost of shipping to the price of a bow but not state it as such. I feel if the post office destroys the bow they should reimburse me for what they charged me.
I put the same bill of sale in the box for bows that I give away, I don't pad the bill and state the value exactly as it would be if I was selling the bow.
I had the post office destroy one osage bow for me, with the bill of sale establishing the value the post office settled my claim in less than two weeks and sent me a check for the amount stated on the bill of sale. This bow was not a freebie, the customer got back what he paid for the bow.
I too am a fan of carpet tubes for bow shipping, I have mailed out about 50 bows with only one damaged. One time I mailed a heavy osage stave and didn't insure it, the post office broke it in two and it was 4" across the back.