Extended warranties are generally not a bad idea, especially with today's finicky circuitry and often-shoddy workmanship. That being said, I have purchased four extended warranties and each time was able to get them for half or nearly half of the cost they were selling for. Depending on the value of your cooktop, as you said, you might not want to bother on that one unless you were able to get the right price for the extended warranty. When I bought my range at a local family owned business years ago, I told them that the extended warranty was too expensive, but that I would consider it if they lowered the price on it. They did. I was just able to get a 10 year warranty for the price of a five year on my current new range... And that one will be serviced by the manufacturer.

Karenlee, After posting this question, I actually read the warranties on the items we're purchasing. Much to my surprise, they have 5-year warranties: the first year covers parts and labor, the following four years covers parts only. Since DH is quite capable, I'm not sure we'd get much benefit from the extended warranty. The cost is $499 for five years on the DW and wall oven. We're going to discuss this with the local appliance shop when we go in this afternoon to place our order. They do refund the entire cost of the warranty if it is not used during the five-year period, in the form of a store credit that is good for two years; but, frankly, I'm hoping that 5-7 years after purchasing our appliances we won't need to be buying something else---and if we do, then we've probably used the extended warranty by then.

If it were $99, I might do it. But $500 is a lot, even if it is 'refunded'.

The one and only extended warranty that I would buy would be if I bought TV at COSTCO.
They already have a 2 year warranty and you can buy 3 extra years for $99 or less depending on the cost of TV.

So $99 for 5 year Costco warranty would be worth it.

In general, I am into "self insurance" - If you add up all of the contract costs and just invest instead of spending -most of the time, you come out ahead.

I only bought one extended warranty - and must have had ESP
We had the Miele DW lemon - but got all of our $$ back after 4.5 years - disclaimer - it was probably not Miele's fault but the incompetent local repair folks - they lost their Miele repair contract.
We did get a second Miele DW after studying DW for awhile - works fine but it does have a warranty.
The other appliances are too new to know if we made a good choice. - but our older appliances were 17 years old (except for DW) when we replaced them - and still going strong...
More appliances are going with longer coverage - I heard Miele now offers a 10 year warranty - woohoo!

Extended warranties are generally a bad idea. Since your DH is handy, save the money and use it to buy parts, if necessary.

Thanks for the answers. We decided not to get the extended warranties, especially since the most expensive parts are covered for 5 years.