The news is full of this:
Found in a basement in New Jersey in 2015, listed for auction in September that year as “Continental school, nineteenth-century” price: $ 800. Auctioned for $870 000 to two Paris art dealers, Talabardon and Gautier, and then re-sold to billionaire Thomas S. Kaplan for about$3 to $4.4 million. Now part of the Leiden Collection. Golden Age indeed.