I was curious how expensive marble actually was, so this is my attempt at looking at historical archives: Tiles were ~1" thick: https://archive.org/details/The

I was curious how expensive marble actually was, so this is my attempt at looking at historical archives: Tiles were ~1" thick: https://archive.org/details/TheBookOfVermontMarbleAReferenceBookForTheArchitecturalProfession/page/n39/mode/1up https://archive.org/details/TheBookOfVermontMarbleAReference... Using an 1889 price book, it cost ~$0.25/ft2 of tile. Add $0.70/ft3 for shipping to St Louis, which is $0.06/ft2 of tile @ 1" thick. That's ~$0.30/ft2 total in materials. https://archive.org/details/pricelistrutland00verm/page/16/mode/2up https://archive.org/details/pricelistrutland00verm/page/16/m... 50' x 50' x 10' building, (floor:(50 x 50) + walls:(4 x 50 x 10)) = 4.5k ft2, which @ $0.30/ft2 is $1,350 of marble. For comparison, - Average annual wages look like ~$700: https://babel.hathitrust.org/cgi/pt?id=mdp.39015002738212&view=1up&seq=609 https://babel.hathitrust.org/cgi/pt?id=mdp.39015002738212&vi... - A 50'x50' 2 story house was probably $4-5k: https://archive.org/details/gfbarber1905/page/n20/mode/1up https://archive.org/details/gfbarber1905/page/n20/mode/1up So adding the marble interiors may have been 25-33% of the price of a house. If the average US house today is $400k, then that's $100-130k for the marble interior.