it's not the throw and catch you have to worry about, it's the 6' fall from the high speed conveyor onto the concrete floor of the sorting center. Onc3 you realize that is the major risk, you can pack accordingly. IOW, after packing, the item should be able to survive a 6' straight drop onto concrete, hitting on a corner. Also make sure that the item cannot shift AT ALL inside the box. Last time I sent a high value item by UPS, insured for $3K, they shook it like a maraca (I knew that the cable could not be damaged) and when they heard it shift the tiniest bit, they opened it and added more padding. Also remember that the insurance is mostly good only when they lose something, which is not very often. Otherwise, they will fight like the dickens to avoid payment. In that regard, the post office is MUCH better.
And there is no doubt that it is the seller's responsibility to pack it safely and make sure it arrives undamaged.
And there is no doubt that it is the seller's responsibility to pack it safely and make sure it arrives undamaged.