The fear of haggling has plunged many a car buyer far deeper into debt than he ever should have gone. In its milder forms it simply takes the fun out of shopping; in extreme cases it destroys the victim's good judgment, ties his tongue, weakens his will and wrecks his ego.

For years I suffered from acute Hagglephobia. I once forked over full price for a dying dinosaur after a used-car salesman reproached me for presuming to negotiate. It was only afterward when my description of the deal caused fellow workers to explode with incredulous laughter that I realized how badly hoodwinked I had been. The sting of humiliation was therapeutic. I vowed to shop with a vengeance for my next car.

When my dinosaur's sudden, undignified demise left me scrambling for a replacement, I promised myself a new car. Unfortunately, for all of my determination to haggle tooth and nail, I was not prepared for the first salesman I encountered.

First off, he served me coffee and doughnuts, which left a mild aftertaste of indebtedness. Then he rhapsodized about the baseball team whose emblem was emblazoned on my T-shirt. In no time I was straining mightily to maintain an adversary relationship.

My position was further weakened when I made the cardinal error of openly falling in love with a car, instead of merely showing an interest in it. This made it a cinch to sell me all of its superfluous accessories.

Finally, when it seemed my price ceiling would be blown sky high, I began to get skittish. But it was too late; the salesman was not to be denied. His charm suddenly gone, he informed me condescendingly that the hundreds of extra dollars I couldn't afford amounted to a pittance: $15 per month.

I swallowed hard; the coffee and doughnuts were repeating on me. The salesman wrote down his final figure and underlined it with a flourish so violent that I jumped. I capitulated and signed every piece of paper shoved under my nose.

There was no incredulous laughter at work the next morning because I was careful to lie through my teeth about the deal. But every month at payment time I privately gnashed those same teeth. And even after my final payment early this year I was still vowing to go to my grave before buying another car.

That is, before Lecture A from my assertive, 68-year-old grandmother. The diminutive, New England-born lady has not only overcome her own fear of haggling, she has taught others to do the same. In her lecture to me, she debunked straightaway the misconception that haggling is a rare skill:

"To haggle with a car salesman you needn't be a clever debater or a master of repartee. You need only remember that you have the upper hand, the one that signs your name. So why attempt to match wits with salesmen?

"Why argue the merits of rear-window defoggers or the efficacy of dual horns? Simply promise to buy a car that day if your impossibly low price is met. When the salesman can't meet it, challenge him to come as close as he can.

"After you've got his best figure, withdraw politely. Often this maneuver alone brings the price tumbling down. But be patient. Visit at least four or five dealerships and signal your readiness to buy. Then go home, pick up the phone and play one dealer's price against another's.

"When you're nestled in the comfort of your home, the salesman can't crowd you or study you for signs of wavering. Indeed, he has to try that much harder just to entice you back into the showroom. And if he doesn't, it's always easier to hang up than to walk out on him."

After I described the psychological battles I had lost, my grandmother decided I was a special case and coached me more on how to turn the tables on manipulative salesmen.

When the big day arrived, I donned a specially made T-shirt bearing the likeness of James Watt dressed like a lumberjack and grinning wickedly as he wielded an ax in a wooded area clearly marked NATIONAL PARK.

This drew quizzical stares from everyone in the showroom except my salesman. He brightened and said he was pleased to meet a fellow fan of the "hardworking" Interior secretary.

"I think he's dangerous myself," I said, explaining that I wore the shirt only to get a reaction and that his was disquieting. The salesman never seemed to recover; an hour later I withdrew with his "best" figure.

At the next dealership a cup of coffee was set before me. Under coach's orders, I drank it and feigned queasiness almost immediately. When the concerned salesman tried to absolve the coffee, I insisted I felt great until the minute I drank it. He never quite recovered, and I left a little while later with his "best" figure.

The next salesman kept getting honest with me, backing each of his claims with some reference to his integrity. I finally floored him with my coach's recommended line: "I believe you. As far as I'm concerned, your honesty is unassailable. But your price is too high."

The price fell dramatically as I was leaving.

Ensconced at home that afternoon, I orchestrated a small price war among the dealers. Every salesman I spoke with was left with the strong impression I was on the brink of returning to the showroom to sign the papers.

All afternoon I teetered joyously on this brink while frantic salesmen, my erstwhile bullies, tried to outdo one another to coax me back. Finally, when the price was right, I bought a car.

The transition from ruthless customer to proud owner was not without a hitch. My coach had warned that the sense of power one gets from upper-hand haggling can be intoxicating, and I must confess that during a giddy moment I phoned the White House and offered to negotiate with the Russians on the arms race.

The nice man on the other end explained that what they needed was a lower-hand haggler. But he said to call him back if I had any luck negotiating my new-car warranty repairs.