Before reading this guide, make sure you are level 40+ and have at least 40k.
Step 1: Go to Luna, not that hard!
Step 2:Walk down into Eucar, and up 1 of the ramps.
Step 3:Talk to the Smith and buy as many Storm arrows as you can bet leaving 5k left over.
Step 4:Go down the ramp and up to the station.
Step 5:Go back to Junon and head to Zant.
Step 6:Setup a shop somewhere and sell all the storm arrows for 100z each!
Step 7:Go eat dinner
Step 8:If all arrows are sold, repeat this guide for as long as you want.