Notes

In TS2 when I needed Sims to have individual funds, separated from the household funds, I used to give them certain decorative objects that had the value of the money I wanted them to have as their own. It wasn't a pretty system, but it worked and as long as you put the object into the inventory on the day of the purchase, it's value stayed the same. In TS3 however, the value of an object will decrease the moment you go from buy mode to play mode, and on top of that, not all objects can be placed into the inventory. So to get around this problem, I cloned the moneybags.
There are 5 different money bags valued 10, 50, 100, 1000 and 10 000 simoleans.
You'll find the bags in the same category as the easel (study -> hobbies).