Extended Warranties
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Another hitch to avoid with our hypothetical big-screen TV, or virtually all electronic goods for that matter: What to make of the offer for an extended warranty. These plans purport to tack on buyer protection for sometimes as little as a few bucks. And in the midst of a big-ticket purchase – when your nerves are most vulnerable – they certainly seem like a safe and even reasonable hedge against those moments when an item suddenly goes on the fritz while you're still paying it off.

Unfortunately, for most categories of items, these plans are almost always a bust according to 'Consumer Reports,' among others. The organization brands them as "notoriously bad deals" and points out that some repairs already are covered under the manufacturer's standard warranty. It also says that today's products overwhelmingly last longer than even an extended warranty in most cases. And on average, 'Consumer Reports' found that repairs to an item under extended warranty cost only a bit more than the extended warranty itself.

When it comes to electronics, there are perhaps two exceptions, though, when you should consider saying yes: for laptops that you'll be traveling with a lot (make sure the warranty includes theft and accidental damage) and for extended tech-support coverage for Apple computers, which is just a year compared to three for many PCs.