First off, you need to bypass HackShield with what is called a bypass. That makes the software that was recommended, a Cheat Engine or CE for short, become a Undetected Cheat Engine, or UCE for short.
As for having lots of money, you can change the money amount with a UCE so it appears that you have a higher amount, but it won't be there on Nexon's server's because GP is server sided, so you can't spend it. After you purchase an item, the original amount of GP minus the amount of the item purchase will be displayed. All the GP hacks were patched.