Time,

When asked to name a valuable resource, most people say money. While that is a very valuable resource, many fail to see just how valuable the resource of time is. If you think back to why the price controls of gasoline in the 70's were such a nightmare, you'll see that it was because much of people's time was wasted waiting hours in line just for gas. The gas was cheaper in price, but not in cost. Time is not free.