Gal Wiener, chief executive of Winner's, called the note "outrageous."
"She didn't want to meet famous people. She was modest and he left her a note," he said. "You know nowadays the 'Me Too' campaign? Probably Einstein would have been in this campaign by leaving such a note to this lady."
Tuesday's auction also included a 1928 letter from Einstein to his colleague Herman Muntz, in which the auction house said he laid out ideas for his "Third Stage of the Theory of Relativity," and a photo of Einstein smoking a pipe. The letter was sold for $103,700. The photo was unsold.
The auction house did not disclose the buyers.
Last October, Winner's sold another Einstein letter with his thoughts about happiness for $1.3 million.
"We've been selling Einstein items for quite a long time now and we have a tremendous success," Wiener said. He said people around the world "are interested in Einstein, not just the mathematical, the physical part, also his personal life."