GENEVA, APRIL 3 -- In the cavernous white tent where the last treasures of the duke and duchess of Windsor were auctioned off today, the nondescript, middle-aged Middle Eastern man with glasses sitting in the fifth row at first passed unnoticed.

But as the auction moved from the last of the late duchess' jewels to the personal possessions of her devoted late husband Edward -- prince of Wales, briefly King Edward VIII of England and, after he abdicated his throne to marry the American commoner he loved, duke of Windsor -- Sam Moussaieff began to nod his head. Soon everyone took notice.

For at each nod in the direction of auctioneer Nicholas Rayner, the price jumped by $6,666 (10,000 Swiss francs) on whatever items seemed to catch the Iranian-born dealer's fancy.

Many items did during the marathon five-hour bidding war for 210 lots auctioned off in the tent set up on the fashionable promenade of Lake Geneva on this second and last day of the charity sale. The Windsor treasures were bequeathed by the late duchess to Paris' famed Pasteur Institute, considered a world leader in AIDS research.

When Rayner, flagging and almost hoarse, pounded the gavel on the auction's final item -- a George III silver-gilt horse-race cup that went to Moussaieff for $200,000 -- the audience stood up and applauded the soft-spoken dealer, who runs a jewelry shop in the London Hilton hotel.

In the course of the afternoon and early evening, Moussaieff's quiet nodding had won him more than 26 lots of the duke of Windsor's memorabilia -- ranging from old silver and alabaster frames with pictures of the duke or his royal parents, to a cigarette case, to royal and personal seals, palace candelabra, ceremonial swords, drinking tankards and the sealskin sporrans that he wore over his kilts.

Though an anonymous buyer paid the day's record price of $1.3 million for an inscribed Royal Navy officer's sword, given to the then-prince of Wales in 1913 by his father King George V, Moussaieff was the day's big spender, plunking down more than $4 million of the $16.7 million in sales that brought the total for the astonishing two-day auction to $50.2 million.

"I haven't decided what I am going to do with all these purchases," Moussaieff said later, as buyers began to file out of the tent and across the street to the bar of the Beau Rivage Hotel to revive themselves. "But I will definitely take them all back to England, because that is where they came from and that is where they belong."

Though there was a suspicion that Moussaieff might have been buying many of the items for Mideast sheiks or exiled Iranian millionaires, the shy, retiring gem dealer insisted that was not the case. "I have always been an admirer of history, and I have long collected historical things," he said. "I admired the duke of Windsor and am delighted to have been able to acquire so many of his belongings and treasures."

Others delighted with the auction were Sotheby's, the international auction house, and the Pasteur Institute, both of which cleared millions more from the sale than their wildest dreams imagined.

When the auction opened Thursday night with the sale of 95 lots of lavish jewels of the duchess, the former Wallis Simpson, the Pasteur Institute said that it would use whatever money was raised to expand and fund its continuing research into retroviruses, cancer and AIDS.

Tonight, Parisian lawyer Suzanne Blum, the administrator of the duchess' estate, said with understatement, "The mission that the duchess asked to fulfil has been more than accomplished."

The duchess of Windsor, who died last year, apparently chose to leave her treasures to the Pasteur Institute because she felt she owed something to France, where she and her husband lived in exile. They had been forbidden to settle in England after he abdicated in 1936 to marry her six months later, upon her divorce from her second husband.

Sotheby's officials were equally astonished at the unexpected success of the auction.

"I'm incredibly surprised. This surpasses even our wildest estimates," said John D. Block, Sotheby's New York-based senior vice president in charge of jewels and precious objects. "We are still analyzing the results, but there is no doubt that they were extraordinary."

One reason, he said, was the desire of buyers to own mementos of the legend of the king who gave up his throne for the woman he loved.

One four-piece lot, including a plain platinum wedding band given the duchess by her husband, went up to $120,000 in a dizzying 40 seconds, almost 200 times the estimated price.

A modest gold medallion commemorating the death of "our principal wedding guest" -- the couple's cairn terrier, "Mr. Loo," which died of a snakebite shortly before the ceremony -- sold for $73,320. Interest was unabated even for trinkets such as a gold pipe cleaner given the duke for Christmas 1945. Listed in the sales catalogue as "slightly imperfect," it still brought $20,000.

Beyond the romance, Block said, there was the "surprising willingness of buyers to overpay because they were delighted with the charity -- the AIDS research -- that their purchases are going to finance."

Bidding was slower on items not connected with the grand love story. Four wedding rings, including ones from the duchess' two previous husbands, both Americans, sold for a mere $16,665.