According to a report just in from Riviera Radio Daily News today
"Car rentals -According to a recent survey renting a car in Nice has increased by 4% between 2014 and 2015. The report carried out by Carigami has shown that the average cost of renting a car in Nice is currently 35.5 euros that’s 4% more than last year. Nice however still remains cheaper than Saint Tropez"
If you are thinking of hiring a car in France follow this link