From the WIKI, GM Commands list, you can find this command:
Code:
#npcloot [show/money/add/remove] [itemid/all/money: pp gp sp cp] - Adjusts the loot
Usage:
Target a fire beetle or any other NPC, and type #npcloot add money 30000 0 0 0 (i think)
This will add 30kpp to a fire beetle. Kill. Loot. Enjoy!
There's probably easier ways to insert coin into the game, but I have not found it yet. So laugh all you want, ubers! I like mugging defenseless beetles for their hard earned cash.