I think my metric is fine. The link you just quoted says "Including human capital such as skills, the United Nations estimated the total wealth of the United States in 2008 to be $118 trillion" - up to you if it's higher or lower 8 years later. His estimation is still low.
Anyway value is not usually priced in terms of wealth, though - but on the future.
"U.S. household and non-profit organization net worth rose from $44.2 trillion in Q1 2000 to a pre-recession peak of $67.7 trillion in Q3 2007. It then fell $13.1 trillion to $54.6 trillion in Q1 2009 due to the subprime mortgage crisis. It then recovered, rising consistently to $86.8 trillion by Q4 2015"
Anyway value is not usually priced in terms of wealth, though - but on the future.