This graphic comparing costs and life expectancy (and doctor visits) is interesting: http://blogs.ngm.com/blog_central/2009/12/the-cost-of-care.html and appears to be well researched.

I ship porcelain vases and pottery regularly. About 100 packages a year (all high value > $1000) and get 1 or 2 breakage claims a year. I double box (external is double wall), use lots of peanuts, airbags, egg carton Yes, UPS ground insurance claims are automatically denied 1st time round, but they pay up eventually. Ground gets more breakages that air (ground is handled more often) and 'fragile' labels are not worth anything. A few international shipments each year get sent FedEx 'cos they handle the export paperwork better! Get the UPS guy out to train you how to pack fragile stuff - it's worth the embarrassment. Overall the results from this test are exactly what I'd expect.

Step 5. is invalid. since a=b, then a-b = 0. You are dividing both sides by 0 which makes the next equation indeterminate. Just for those who don't do algebra...