Fund manager Geoff Wilson has doubled down on his commitment to Warren Buffett's idea of using permanent capital to build wealth with a takeover bid for mobile virtual network operator Amaysim.

Wilson's WAM Capital, is offering 69.5¢ in cash, or 83.32¢ worth of WAM Capital shares, for each Amaysim share. The big prize for Wilson is $80 million in franking credits sitting on Amaysim's balance sheet.