With its A-list invitations, racks of designer rags and a late supper of coq au vin, the Seventh on Sale AIDS benefit Nov. 29 in New York City was haute (monde), haute (couture), haute (cuisine). For some it was also hot, as in tempers, when 1,300 members of so-called polite society paid up to $1,000 each for the opening-night privilege of haggling over high fashion at bargain-basement prices.

To triumph, shoppers had to know the rules of the game—she who tags it, bags it. So Diane von Furstenberg ceded a $900 (originally $3,500) Oscar de la Renta foxtrimmed bolero jacket to Ivana Trump. But best-dressed perennial Nan Kempner wasn't as giving when it came to a $32 hat. Miffed that the fruit-bedecked Badoglio straw number she had put on hold had disappeared, Kempner located it atop designer Malee Chompoo. When Kempner plucked it off her head, Malee's partner-husband, Kazuyoshi Hino, challenged Kempner—whereupon she slapped him. "It was my first reaction," Nan explained.

In the three days following the kickoff dinner, 13,500 seasoned shoppers paid $10 (good for 2½ hours) to compete for 80,000 items donated by designers and department stores. The charitable result: more than $4.5 million raised for the New York City AIDS Fund. For those who braved the lines outside the 69th Regiment Armory, the payoff was a crack at such steals as a $10,000 gold-sequined Chanel jacket for $500. "I got four shopping bags full, I was so hysterical," said Pat (Mrs. William F.) Buckley. 'it's all for such a good cause. And I love a bargain. Doesn't anyone who usually buys retail?"