Hacking money in contracts (Hitman: Absolution)

In contracts, you can make a lot of money that way:
1. Go to Artmoney.
2. Select the process Hitman Absolution.
3. looking for the price of any gun(suggest Kazo TRG, because only she stands 1600000).
4. Change the value say on -200000000.
5. Exit the shop and go back.
6. Buy our Kazo, which is now worth -200000000.
7. Happy 200000000 money in your wallet!