Prodigality is excessive or extravagant spending. Your friend may feel he needs those gold chairs for his living room, but to everyone else it’s another example of his prodigality.
“Idleness is the greatest prodigality,” said Ben Franklin. He was probably right, but today prodigality is more often used to talk about spending monetary resources, as opposed to other kinds of resources. Prodigality does not merely refer to spending above your means. It’s excessive or wasteful spending, often with an eye toward the luxurious. Think of the Palace of Versailles, or that film star who owns ten expensive cars but doesn’t drive. Synonyms for prodigality include extravagance, profligacy, and lavishness.