Mark Walter isn't that rich on his own but he is part of the Guggenheim Partners, who own assets to the value of $200 Billion Dollars!!
I wasn't really sure what that would mean in regards to investment of a club, but they have purchased the LA Dodgers and just as an example of the money they have pumped into them:
'On January 15, 2014, the Dodgers agreed to a seven-year, $215 million, contract extension with pitcher Clayton Kershaw. The deal was the largest contract for a pitcher, ecliping Justin Verlander's deal from the previous year.[26]'