Earn easy credits w/o codes
You must first purchase the Supernova or Martial Law add-on pack for the game. Once this is done, you can now go to any store in the game and purchase the Heavy Duty Detonator for free. Turn around and fire your three mines on the floor anywhere around you. Use the Alt fire button to pick them back up and without reloading, go back into the store and sell the Detonator along with the mines. This will net you $600 each time. Repeat as many times as desired. Enjoy!!
Added by: moneymike08 Feb 3rd 2011, ID#3569