"Princess Daisy," the yet-unpublished novel by "Scruples" author Judith Krantz, brought a record $3,280,875 for the sale of its paperback rights to Bantam Books late Wednesday night.

The figure exceeded by $730,000 the $2,550,000 paid last year by New American Library for paperback rights to Mario Puzo's "Fools Die." The previous record had been held by "The Thorn Birds," which went for $1.9 million.

The sale was conducted by Crown Publishers, Inc., hard-cover publisher of "Princess Daisy," in a 14-hour telephone auction with a minimum bid of $1 million. Seven paperback houses bargained; five -- Fawcett, Avon, Warner Books, Bantam and Ballantine -- topped $2 million. At 11:35 p.m., Ballantine refused to top Bantam's unprecedented offer by the requisite 7.5 percent and ended up without the book.

Krantz, a 47-year-old former Cosmopolitan magazine editor, entered the literary marketplace two years ago with "Scruples," her first novel, about a Beverly Hills boutique of the same name, run by a girl named Billy Ikehorn, an ugly duckling who becomes a wealthy playgirl. Warner Books reportedly has sold 3.4 million paperback copies of that book in less than a year.

The author spent the day of the big auction steaming the wrinkles out of her clothes:

"My husband and I had just come back from Avignon," Krantz said yesterday from Aida Grey, a Beverly Hills beauty parlor where she was having her weekly hair treatment and her first pedicure in six weeks. "Everything was wrinkled and I was using this little thing called a Wrinkle-Away to straighten them up. It was very soothing to my nerves.

"We were too nervous to go out to dinner, so I cooked hamburgers and we watched the telephone. It was a long day. I didn't even think to turn on the television. At 11 o'clock a reporter from the New York Times called and asked how old I was, and then he hung up and I went to bed. I woke up at 6 o'clock yesterday morning and called my mother in New York. It was 9 o'clock there. And she said, 'Oh, do you think they can afford it?' "

"Princess Daisy" is, as might be expected, the life story of one Princess Daisy, daughter of an American movie star and a Russian prince. It begins in St. Petersburg in 1910 and moves through three generations and two continents, with forays into a California college in the '60s, the New York television industry, the horsy set in Middleburg, Va. and Manhattan's Tavern on the Green (where a party is held for the princess, as one will be held for Krantz when the hard-cover is published on March 9, 1980, the second anniversary of the publication of "Scruples").

"It's not an epic, not a saga," says Krantz, "just a hell of a good read."

"This is a book that will pull people into the bookstores," claims Bantam president and publisher Marc Jaffe, who is well aware of the recent slump in book sales. "We expect this book to be in a league with "The Exorcist' [reported paperback sales: 11 million], 'Jaws' [10 million] and 'Valley of the Dolls' [9 million]. There's nothing like a big best seller to pull the industry along."

All three of those novels are published by Bantam. The best-selling paperback novel of all time is "The Godfather," with 13 million copies of the Fawcett edition in print. "Princess Daisy" will have to sell between 4 million and 6 million copies, depending on its cover price, for Bantam to recoup its advanced.

"We're going to have a first printing of 150,000 copies," says Crown Executive Vice President Alan Mirken, noting that "Scruples" sold 220,000 hardback copies for the company.

"This is a book that captured the million-dollar enthusiasm of eight publishers." he enthuses. "This book will be established in 1980. We'll spend $150,000 in advertising. It could turn the industry around . . ."

And in Beverly Hills, Judith Krantz -- sitting under the hair dryer -- was writing away in longhand at her third novel, still in its planning stages, a tale set in France.

"I'm a compulsive writer," she said yesterday.

And then:

"Oh, I guess now I'll have to increase my tipping habits here or they'll call me cheap."