How much to build a Beaus Arts-style building today?

I happened to catch a show on the History Channel abou the Jefferson Building at the Library of Congress. It stated that the building cost $6 million dollars in the 1890s - an amount that would still get you a decent-sized structure today. That got me wondering. How much would it cost to build a Beaux Arts masterpiece like Grand Central or the Palais Garnier in today’s dollars?

Oopps, that’s what I get for typing this on a phone. Can a mod please fix the thread title to correctly spell Beaux?