Andy Warhol sold one of his largest flower paintings to Isabelle Collin Dufresne (who would eventually adopt the moniker Ultraviolet) for today's equivalent of about $5,000 USD. Hardly comparable to some of the sums fetched by today's top working artists, but here's the thing; his rent for The Factory, the legendary space that was his art studio, production house, and entourage hangout was no more than $150, the equivalent of close to $1,500 today.
For context, the Factory was 5,000 square feet and located in Midtown Manhattan. It was by all accounts beyond dilapidated, but still a massive centrally located space in America's densest city. The best you could hope for for that kind of money today is little more than a closet and chances are it wouldn't even be so centrally located.
Another way to look at this is: The sale of one painting could cover the cost of over 3 months' rent.