TO my mind, Lafayette is by far not the best store for niche shopping in Paris. I'd rather recommend you to go across the street to Printemps, they have an outstanding niche perfumery department at the ground floor.
I would look for exclusive Guerlains (they have some of them), Maison Francis Kurkjdian, Houbigant, L'Artisan or Frederic Malle. That way french brands![]()