"Self Portrait (Fright Wig)", Sachs' by long-time friend Andy Warhol, was the night's top lot, going under the hammer for $8,479,889 (€6,629,730) at the Sotheby's sale, which raised $56,353,203 in total.
A Warhol portrait of Bardot which Sachs commissioned in 1974, five years after the couple divorced, realised almost $5 million.
Sachs wooed Bardot by having a helicopter fly over her villa on the French Riviera and shower her with hundreds of red roses.
The couple married a few weeks later on July 14, 1966, in Las Vegas.
Sachs commissioned many of the pieces himself or purchased them directly from the artists for his apartment in the Swiss Alps resort of St Moritz.
In 1972, Sachs put on Warhol's first major European exhibition at his Hamburg gallery. He spared Warhol's blushes by secretly purchasing half the works when there were few buyers.
Sachs took his life at his Swiss chalet a year ago, explaining in a suicide note it was due to "no hope illness A", thought to be Alzheimer's.
Bardot said she was "literally destroyed" by the news of his death.