F. Scott Fitzgerald was paid $4,000 for "Babylon Revisited" – in 1931. That's the equivalent of over fifty thousand dollars today. In a letter to Ernest Hemingway, he described himself as an "old whore" whom the Post now paid "$4000 a screw." (Source: Kirk Curnutt, Cambridge Introduction to F. Scott Fitzgerald)
Both Fitzgerald and Hemingway used to frequent the Ritz Bar in Paris, the joint that frames "Babylon Revisited." (Source)
The Ritz bar also appears as a setting in Fitzgerald's short story "The Bridal Party" and his novel Tender Is the Night.
In "Babylon Revisited," Charlie is disgusted at the memory that he stole a butcher's tricycle and pedaled Lorraine all over Paris with it in the wee hours of the morning. Fitzgerald, in 1929, stole a baker's tricycle and pedaled all over Paris with it, "thumping the Russian doormen with a long loaf of bread." (Source: James R. Mellow, Invented Lives: F. Scott and Zelda Fitzgerald. Boston: Houghton Mifflin Co., 1984.)
Fitzgerald wrote a screenplay version of "Babylon Revisited." There were plans for Cary Grant to play the part of Charlie Wales. (Source)