Investing icon Warren Buffett took his own advice Tuesday - getting “greedy when others are fearful” - when he ignored the banking-sector bonfire and slapped down a cool $5 billion for a stake in Goldman Sachs Group Inc. (GS). By literally putting his money where his mouth is, Buffett’s actions - and reputation as a shrewd bargain hunter - restored some of Goldman’s luster and helped bolster investor confidence in the U.S. banking system.