Talk to the lady and lure her to the GURAD SHOP. While after her text, while you are also shopping. Now move around with the control stick, and go to the green shop. (Or orange whatever) If it says "BUY/SELL" press "B".

And press any buttons, and look! You're walking around with that text! Now walk to the BANK, and talk to the woman. The shop list must scroll upwards before reaching her. Now around "TAKE/DEPOSIT", go to TAKE, ITEMS, now take any items. When it says "YES/NO", press "B" twice, and press DEPOSIT, and you're walking around with that too!

Press B. Now TAKE all your money, and back to "TAKE/DEPOSIT" screen, now press START/DEPOSIT same time, both on ITEMS, and scroll down where the money is, now deposit an item, when it says "YES/NO" and the money about to drop, press B twice.

Now the crusor is on the MESETA and the other is on DEPOSIT, press A and do MESETA, now DROP/DEPOSIT all the money. And the money should be in the BANK and one's in front of you!

You can do this as much as you want now! It takes time to get used to though, watch Youtube for further details. Good luck!