by HelloTechWhen you are healthy, you will sacrifice all your health for money. When you are ill, you will sacrifice all of your money for health.
If you're an idiot.
It's convenient, certainly easier to carry than the things they're worth. Can you imagine how annoying it'd be to follow a bartering system purely of trading the items themselves? Heavy items would suck to lug around, and the very fact that it is heavy would dissuade trades.
I suppose backpacks and other means of carrying items would skyrocket in value.