Paul,
don't mean to be a wet blanket, but most add on warranties are super profitable to the issuers.
There is a saying in the insurance business that one should not insure what one can afford to replace without hardship.
If replacing a 30 dollar sander would be a hardship to you, and the cost of the warranty is small, then fine.
For some that's a 300 dollar saw. For others, a $3000 lathe. It's usually better to take the money you would have spent on warranty on items under a hundred bucks and then use the higher amount to buy better quality, if you can. Simply a better use of your money.
An extended warranty is really a type of insurance for unforeseen and undesired expenses.
And it is rarely good value to buy insurance on lower valued items. Which is why many of us carry 250, 500 or 1000 deductibles on our cars, boats, combines, whatever. Besides, you put in a couple of nickle dime claims and get nonrenewed, all of which is recorded in an industry database that most companies access during underwriting.
The only time I bought a warranty was for electronics I installed on my boat, like tvs, dvd players, etc. The boating environment is harsh, lots of vibration and shaking, so I could really imagine that ruining something.
And in thirteen years of owning that boat, which thank goodness I no longer own, not one piece of electronics broke.
So how smart was I?...