Gandhi wrote to Hingorani for around two years after the death of his wife, Vidya, offering him guidance, consolation and encouragement. The messages were later compiled in a book called, A Thought for the Day.
Dinesh Vazirani, co-founder of Saffronart, said the collection allowed people to see Gandhi "through the lens of a close, personal relationship".
The notes were the highlight of Saffronart's "86-lot" auction, titled Gandhi: From the Collection of Anand T Hingorani. The lot also included letters, manuscripts, photographs and personal objects preserved by the Hingorani family over generations.
The collection spans more than two decades, documenting key moments in India's independence struggle as well as Gandhi's friendship with Hingorani.
"These reflections offer a rare insight into how Gandhi lived the principles he advocated publicly, making this an especially valuable record of his thought and practice," Vazirani said in a statement.
Other items in the auction were Gandhi's notes on God and the Hindu holy book Bhagavad Gita, his portable spinning wheel and two letters about the spiritual discipline of spinning.
Saffronart has not disclosed the buyer's identity but said the notes would remain in India.
