I have $16,342,433,473,660,221,195,642,089 (or, 16 septillion, 342 sextillion [sounds bad but its not], 433 quintillion, 473 quadrillion, 660 trillion, 221 billion, 195 million, 642 thousand, 89 dollars) in story mode (completed)
I found some awesome way, easy to earn money on Story Mode, you must have Level Max Jet, Level Max Nuclear Reactor, and equip 3 Stages Level Max Sonic Burst. Boosts not required because once your lift off, watch what would happen XD, I tell ya, this will also work if you want to destroy the moon if you have not yet completed the Story