Doubtless the accommodations for the man in the iron mask on the Île Sainte Marguerite were not in the style of the Hôtel du Cap so near and yet so far just a few kilometres across the azure water to Cap Ferrat.
However his dungeon was free of charge.
And believe me, food, beverages, laundry and tips can well bring that close to double.
If he had chosen a suite or villa his bill would have cleared the national debt of many former French colonies.
It is worth noting that only fairly recently did this and many other luxury hotels in Cannes accept credit cards, previously requiring cash in settlement. They also imposed minimum stays (ten days during the film festival), charged a full booking for early departure, and demanded 50% of the reservation in advance — non-refundable. Naturellement!