Easy Money
An easy way to get money is have a friend who has a lot of money. Go to any level and raise your power gauge to max. Keep on pressing Y on your partner. You will receive 50 gold every time you hit them. Complete the level and you'll have lots of money.
How to unlock 6th Class
Go to the class select screen and highlight the classes and press quickly Pirate, R Trigger, Thief, R Trigger, Warrior, Trigger R, Archer,R Trigger, Pirate, R Trigger, Warlock, R Trigger, Thief, R Trigger, Warlock, R Trigger, and Thief, R Trigger.