QuoteWhy "rags" live at the top and "riches" on the bottom?
To me it wouldn't make sense.
I wouldn't be so categorical. Many fictional works use the "higher=richer" trope as an easy metaphor (Metropolis, The King and the Mocking Bird...) but it's not always true in real life.
Traditionally, the "noble floor" was the first floor. In many old buildings, the more ornamented flats with higher ceilings are located at this floor.
Nowadays, the lower flats can still be more expensive than the higher ones if a building doesn't have an elevator (sometimes there's not enough room to install one) or if it's insufficient for all the residents.
Privative gardens at ground floor can also drive up prices.