The letters, put on public display for the first time ever at Geneva's Hôtel des Ventes auction house, shed light on the composer's ties with his German counterpart Richard Wagner and French-Polish composer Frederic Chopin, to whom he dedicated three musical scores.
Also up for sale was an eight-page, handwritten booklet of piano exercises composed by Liszt for his pupil Valerie Boissier in 1832.
The booklet alone, which had been estimated at between 3,000 and 5,000 francs ($3,150-$5,250), went under the hammer on Wednesday night for 16,000 francs, according to the auction house.
One Liszt score dedicated to Chopin, which had been estimated at between 700 and 900 francs, was finally sold for a whopping 43,000 francs.
The lots were part of a broader sale of musicology items, including manuscripts, scores and photographs related to Bela Bartok, Paul Dukas, Nikita Magaloff, Igor Stravinsky, Joseph Szigeti, and Wagner.
They came from two private collections, one belonging to the family of Szigeti and Magaloff, who was his son-in-law, and the other to Genevan musicologist Robert Bory.