In section 2-2 in the mining area, after the cinematic where the masked person takes the man in the suit away, you will have a great opportunity for easy treasure. Immediately in the area that follows is a brilliant diamond worth 4,000 gold and smaller diamond worth 2,000 gold. While you are upstairs, next to the windows will be a locker that you can open. Inside is a sniper rifle in case you need it. Downstairs are two enemies that you should get rid of to make things easier. Then from upstairs, you can pick off the half-dozen or so enemies that are waiting for you outside with the sniper rifle. After you take care of all or most of them, run out. To your left behind all the equipment is a small red ladder. Climb it, and to side farthest from you will be a chest. Inside will be the big brilliant diamond. Go back and walk past the truck with the turret. Look up towards the end of the first long red ladder. You will see a shining spot. Shoot it, and the smaller diamond will drop for you to pick up. In about five minutes or less you will make an easy 6,000 gold. Quit the game and select "Yes" when prompted. This will save your equipment and treasures. Reload, continue the game, and repeat the process. You will soon accumulate enough money to upgrade your weapons. To make even more money, only equip the new sniper and keep picking it up or giving it to Sheva. Also keep selling it to get extra money.