It depends on how you define "expensive." If you're referring to tangible items, the most expensive item ever sold is believed to be the Yacht "History Supreme," which was reported to have sold for $4.5 billion. When it comes to intangible items, it's difficult to quantify the cost, but things like the rights to use a patent, a license to drill for oil in a certain area, or a premium domain name can fetch billions of dollars.
In terms of market value, the most valuable companies in the world are currently tech giants such as Apple, Amazon, and Microsoft, with market capitalizations that exceed $2 trillion.
In terms of market value, the most valuable companies in the world are currently tech giants such as Apple, Amazon, and Microsoft, with market capitalizations that exceed $2 trillion.