Money Money Money

I want a system in my game which enables the player to loot objects and if possible, dead enemies although the latter is a lot harder. I also want an economy system in my game, so the player gets money from missions and looting and then can spend it on weapons, hints, etc. The only problem I'm having is that GoW engine has for some weird and unknown reason had the math expressions from out. This makes it very hard, if not impossible for me to have an economy system which is a bit annoying.

Anyway, here is my first draft of a looting system, it requires the player to be in a trigger volume which would be in front of a cupboard for example, then the player has to 'use', the items/money are then transferred to the player accompanied with a sound effect. I'm thinking about having booby trapped loots as well that can damage the player. I was originally going to have the object flash, either all the time or just when you looked at it to tell the player it was lootable but trying to add a flashing expression to a complex Epic material became  a pain. So instead I just have a message flash up letting the player know you can loot it.