Probability theory already too high for the average Joe consumer!

Which is not surprising that consumers have for simple calculations must be stupid!
We expect gross:
Price of purchased items, or the insured amount divided by the warranty period.
Average 350 / 3years = 8.33 Period
8.33 / Extended Warranty Period 3 years = 2.77
Now would theoretically each 2.7. Device in these 3 years after the first 2 years break !!!
(Loss of value, age of the equipment after the "Normal Guarantee Time" and thereby also changing conditional probabilities are not included.)

Now you should ask yourself:
1. Is my device possibly broken in this time? How likely is that even to determine a quota itself.
2. If it is theoretically so that my device is most probably broken, how stupid am I as a consumer at all, that I have a scrap with the wonderful planned obsolescence of great industry still buy such?

The premium of the insurance is so high unlikely in this case that it is almost already is a usury.
But you remember: money always falls from the bottom up, usually accelerated by the boundless debility of consumers.
Insurance companies are nothing more than "Sports Weather" with the safe margin on its own page. Who already has enough money should not insure. In this case, the amount of 300-400 is certainly manageable!