When you have 30 Coppers press F1 and then 4 to highlight the 30 copper hill. Place the hill somewhere and you will now have -320 Coppers. Save your track and reload it. You will then have 0 Coppers. Press F1 and 1 to highlight the 0 Copper location. Use it to clear the hill, replacing the hill with that ground. You should now have at least 320 Coppers. Repeat this as many times as desired.