What is the most costly item in the world?

What is the most costly item in the world, and how does it compare to the value of cryptocurrencies and other financial assets? Could it be a physical object, like a piece of art or a diamond, or is it perhaps a more abstract concept, such as a company's stock or a rare commodity? And if the most costly item is indeed a physical object, what factors contribute to its value, and how do they differ from the factors that determine the value of cryptocurrencies and other financial assets? Is there a correlation between the value of the most costly item and the overall health of the global economy, or does it operate independently?