With a little cheating and using a bug in the PvZ, you can have thousands of money.
1. Go to Mini-Games in the main menu.
2. Complete any mini-game but when the trophy appears don't click on it. Instead open menu and click on leave.
3. Go back to the mini-game you completed and click on trophy this time and then leave.
4. Until you restart the game, you can repeat step 3 to get thousands of dollars.