It depends on the expected reliability of the item, for example my 50" Panasonic LCD-projection TV. It has a known defect where it blows a $300 bulb about every 6 months. I paid about $300 for the extended warranty and have used it 3 times already in 2 years.
It depends on the repairability of the item, for example a notebook computer is very hard to repair display problems, motherboard problems, keyboard, etc., where the equivalently-priced desktop computer would be a breeze to fix yourself.
It depends on how badly you need an item to be available all the time, and the terms of the extended warranty. For example my digital camera. I can't live without it. My extended warranty is a local repair/replacement warranty, so I can take it to the store, get another one just like it and I'm good to go. If it were a ship-in for repairs type warranty that takes 3-6 weeks for repairs I would die. (well, I'd have to go buy another camera, but I'd do a really melodramatic impression of dying.)
Basically extended warranties are insurance. You assess the risks of what could go wrong with your products and decide if they're worth the price to cover. Always pay attention to the fine print, such as non-covered failures (consumeables), how long it takes to get a repair and whether or not they can be done locally, etc. Whether or not tech support calls are free. How many incidents you can claim on a warranty before its considered "fulfilled".
Are extended warranties worth it?
Yes, I always buy them (tell us why)
No, they?re a rip-off! (please explain)
It depends on the price of the item (for example?)
What's a warranty? (you?re in trouble)
I should?ve gotten one for my boss, he's malfunctioning!

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