Ok, first enable cheat mode(hold ctrl and type GABBI). Then when you play the game up to Estoni(the gas-station/junk yard), get a gun that uses ammo that really expensive. Then, click on the character with the gun /w expencive ammo, take out the ammo, and push alt+R to reload it. Take out the ammo, and alt+R, keep doing this. Then when you get full of ammo, sell it to Jake and get money. Rinse and repeat until you get as much money as you need.