Spend a total of $200 million across all three characters. [Bronze / 20G]

There is an incredibly easy way to boost this trophy / achievement. After finishing the story you should have $20 million available. Open the internet browser, go to the "money and services" tab and open the LCN stock exchange website. Now invest all of your money in stocks and sell them again immediately! You won't lose any money if you sell the stocks quick enough. You can also do this earlier with less money, but it will take longer.
To look up how much cash you have spent, go to "Cash" in the statistics of the pause menu.