Infinite Money:

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 expensive 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.

Enable Cheats:

To use the following codes while HOLDING Down [Ctrl] type iguana to enable the cheat mode. Alternate for version 1.06+ is to hold [Ctrl] and type in GABBI

Display units and objects [Alt] + E
Teleport selected Merc to pointer location [Alt] + T
Kill all enemies in current sector [Alt] + O
Refresh action points of the select Merc [Alt] + D
Ammo refill [Alt] + R
Item scrolling(select item in detail view) [Alt] + W
Spawn enemy at pointer location [Alt] + B
Spawn Civilist at pointer location [Alt] + C
Spawn new Merc at pointer location [Alt] + G
Spawn Roboter at pointer location [Alt] + Y
Spawn enemy bug at pointer location [Ctrl] + O
Merc transforms into bug [Alt] + [Keypad 2]
Merc transformed into big bug [Alt] + [Keypad 5]
Merc placed in wheelchair [Alt] + [Keypad 4]
Spawn random weapon at pointer location [Alt] + I
Explode a gas grenade at pointer location [Alt] + K
Explode a hand grenade at pointer location [Ctrl] + K
View interior of all buildings [Alt] + Q
All Mercs in current sector arrested by Bad Queen [Ctrl] + T
Merc at pointer location loses health points [Ctrl] + H
Merc at pointer location gains health points Ctrl] + U
Display frame rate [Ctrl] + F
Merc Changes to Tank [Alt] + [Keypad 1]
Teleport troops to Selected sector (use at map screen) [Ctrl] + T
Add $100,000 (use at laptop screen) [Plus]
Subtract $10,000 (use at laptop screen) [Minus]

Kill all enemies (use at map screen) Hold [Alt] and click "Go to Sector" icon