If you are going to Nice, I can definitely recommend you to visit the market Marché aux Fleurs in old town Nice. They both have luxury such as Louis Vuitton, Chanel, Dior etc. and ofcourse other second hand. Around the market you find a lot of cafeés and right now (November) it is high season for seafood, just in case you also love Moules Frites, haha. The weather is really good, and you can even wear just a skirt and a sweater.