As a measure of lifestyle, to a degree. Although the anomalies are obvious: the upkeep costs of a lavishly appointed London mansion a multimillionaire owns are certainly lower than the rental on a much smaller flat (and probably a fair bit less than the property appreciates in value). And wealth is a source of power and claim on future spending. The average person spending $100k per annum does not have the capacity to decide nobody in his family need ever work again like Warren Buffett could, never mind his power to move markets.