If I were going to Paris I'd:
-buy the perfume bee's e-book. ($10?). A three-day tour of Paris's perfume stores. Her book was mentioned on basenotes home. I highly recommend it.
-also check out her blog (theperfumebee). she occasionally mentions new places to get perfume (evody to primtemp)
-I'd also hit designer's boutiques like Olivier Strelli and Barbara Bui. Also would try to find if James Heeley*** has a studio in Paris (crazy and obsessed w/ his Menthe). I'd also pop-in to Colette Boutique** to see what they have (also a big fan of Curated by Colette-Bless).
***don't know what happen to his website; it's not around anymore?
** did I read s'where that Colette Boutique is collaborating w/ Ineke for a new perfume?