Even if the percent is 1/2% that is extremely high risk considering the cost to repair. Risk is a two part equation. It is the probability of an occurrence times the severity of occurrence. If the severity is high, even a low probability of occurrence makes for a high risk. I also believe that 1/2 percent is a very high probability. If you had a 1/2 percent overall failure rate on your car, you would consider it unacceptable. That would be like having it not start once every 200 days when you got up to go to work.
Its kinda like Dirty Harry. Do you feel lucky today? I purchased the extended warranty for peace of mind. It's the first time I've ever done that and I know that the manufacture statistically will make money on it, but if I'm one of the unlucky ones who get stuck with a $8K repair bill the manufacturer will lose and I will win. Anyhow, the point of this long winded post is that it is a personal choice based on ones personal evaluation of the risk (not probability - risk). I'm happy with my choice even though it won't be the right choice for others.
When we do risk analysis and risk management professionally, we look at it as (simplified version):
What is the severity of the risk?
What is the probability of occurance of the risk?
What is the chance of detecting the risk before it becomes a problem?
Rank each of those 1 if the severence, occurance, or risk of not detecting it is low. Rank a 3 for those that are medium, rank 9 for those that are high. This is subjective to YOUR tastes. In place of the 1, 3, 9 scoring for severity, you can just put dollar amount there.
Then multiply the 3 values together and see if you can live with that amount of risk exposure.
The second half of this gig is to determine the benefit: List your benefits and rank them 1 for "meh", 3 for "cool" and 9 for "I love it!"
Now take benefit/risk as a number. Can you live with that?
