(NBC) -- It has become a rite of passage in retail.

When you've made a big-ticket purchase of appliances or electronic equipment the next thing the store wants to sell you is the extended warranty.

"One reason stores push them so hard is that there's just a huge profit margin on them, 50% in some cases, a lot more than they make on the products themselves," explains Consumer Reports' Greg Daugherty.

Daugherty led research at Consumer Reports on the value of extended warranties and concluded it's best to just say no.

"Even if you do have one and try to use it, sometimes you get a run-around, it might take a long time to get the product repaired," he says.  "You might find it very hard to take it any place if there's no place near you. So, there are any number of stumbling blocks, even if you do have this coverage and you need to use it"

He says extended warranties are often unnecessary because reputable manufacturers stand behind their products.

"Very often, they will try to fix it even outside of the warranty, just to keep you as a satisfied customer and to protect their brand," Daugherty adds.

Homeowners insurance can offer riders for extended coverage as well, and definitely check the contract with your credit card company.

"Depending on the kind of credit card you have, and we urge consumers to look and make sure, but very often, you will get some sort of extended warranty  coverage with a credit card," Daugherty says.

Another alternative is to insure yourself with a repair or replacement fund in your bank account.