Every now and then I’m moved by an author to praise his or her work. Yet, sometimes a subject, its research, its prose simply bedazzles and in the case of fashion expert Dana Thomas’s book, “Deluxe How Luxury has Lost its Luster”, I’m eager to declare it a feat of business journalism. Having read this book, I defy anyone to enter a brand retail space such as Louis Vuitton, an emporium like Saks, a chain like Gap, or a street vendor’s lair and not rethink the motive for doing so. For Thomas asks only two questions in her tightly packed nearly 400 pages: What is luxury? And given the morphing of its industry model, can it still be found today? Doing so she catalogues the…