He can't make insurance truly "optional" -- no matter what he states in his auction, he is responsible for delivery. In effect, he is forced to pay for delivery confirmation along with insurance, or absorb all the risks. Of course, he can demand a high shipping and handling charge from the buyer, but that discourages sales and is wasteful economically.

When I order something from a 'true' business, the business takes responsibility of delivery. The costs of shipments and associated costs are built into the price. Sellers PROUDLY disclaim responsibility for packing, shipping, or delivery. They put it on the BUYER who has absolutely no control. If I don't buy insurance, or confirmation the seller can keep the item and claim it was shipped. Paypal has stopped that and put some power in the buyers hands. If I leave a neg for a seller who screws me, guess what, the seller does the same for me. Each side needs to take responsibility for their side of the transaction. Sellers have had the control, only recently have buyers had recourse other than neg feedback (which the seller held for ransom). If the sellers were REALLY absorbing the cost and not just complaining about smaller profits they would stop selling. Many, many sellers look at s/h charges as another avenue for a little profit. You KNOW this is true because it has been the topic right here so many times!
There are unethical buyers and sellers out there nether side is lilly white.