I agree with >>2143
It's hard to make everything by yourself.
The thing about our world is that pretty much everything costs money, not just products like clothes or toys. It is very good to go out with friends or family, but if you go out to a theme park or a movie you will have to pay money. As for fair's you often have to pay money just to get in let alone buy food or anything else.
I don't like the money system, but I have no idea how the world would run without it. It provides a standard for trade. Trade used to be that someone might trade a man 5 hens for a cow, or something like that. In that type of trade no one knows what a product is worth since there was no standard.
Also as you said money is just paper, and not worth anything. It used to be that money represented gold, but I still don't see gold as that valuable myself. Still, since this paper money can buy things our economy stays afloat (somewhat).
The reason that our economy would fail if people only bought what we needed is because of supply and demand. If a computer company makes 300 computers a month they need all of those to be bought,if not then they wasted money to make those computers. If the company keeps on over supplying eventually they will be out of money. If people only bought what they needed this would happen to many companies, and the country would fall into depression. Also if those companies failed the people would have no jobs, and therefore no money to buy essential things like food.
I hope taht sums it up.