Shoppers for televisions, videocassette recorders, washing machines and just about any other home appliance have come to expect the hard sell not once but twice: first for the product, then for the extended warranty.

      The pitch is tough to resist. This year nearly two-thirds of all consumer electronics and appliances sold will leave the store with extended warranties tucked in their boxes."It mystifies me," says Susan Greisberg, president of the National Association of Consumer Agency Administrators. "Salesmen go on about why we should buy a particular product. Then in the next breath they disparage it, trash its integrity, push us to buy an extended warranty - and we do," she says.

      Purchasing such peace of mind costs you an extra $20 to $500, depending on what you bought and the number of years covered. Often it's cheaper to simply buy a new appliance.

      Terms for extended service contracts vary widely but generally cover the cost of repairs, yearly checkups and replacement of lemons for one to five years from the date of purchase.

      For at least a portion of the time, you're paying for duplicate coverage - the manufacturer's warranty is good for anywhere from three months to two years.

      Moreover, defective appliances and electronics tend to falter in the first three to six months of use, according to the Electronics Industry Association.

      In fact, more than 80 percent of contracts sold go unused, according to William Sliney, president of the Service Contract Industry Council.

      Since so few products actually need repairs, the profit margins for dealers are out of sight. For every $100 service contract sold, a store can pocket $80 to $96.

      If you plan to use a credit card to buy your appliance, you may be covered for an extra year of repair work anyway.

      MasterCard (800-622-7747) and Visa (800-847-2911) gold-card holders get double the manufacturer's original U.S. warranty for up to one year on most purchases.

      Holders of regular Visas and MasterCards are sometimes covered.

      American Express (800-225-3750) also offers a one-year extension for warranties of less than five years. To qualify you must register within 30 days of purchase.