Okay, if you seem to win at Chance Items, or maybe you have some Gaia Cash, alot of Chance Items, when you get to the final stage, instead of getting the item you can leave and sell the Final Stage, which most of the time sells for alot.
About each Famestar Hero final stage (since you can choose between bands) sells for around 900k. And last time I checked, Famestars themselves cost 100k, so if your lucky, you could make some easy money.
I did it for a while, and I got around almost 2mil, but I was stupid and kept doing it, even after I lost. So, don't do what I did, and dont kept on doing it even though your luck has seem to run out. I went from almost 2mil to 90k.