Living frugally means understanding the variables of currency. Everything costs, but it does not cost the same thing. This is not a discussion about exchange rates between countries. This is a presentation of the three items of value we often use interchangeably to attain what we want: money, time and energy.
We are most familiar with the concept of exchanging money for goods or services. However, frugal living takes into consideration that those goods and services could perhaps be obtained through other (legal) means.
Time is an interesting currency because every person on the planet is given the same amount each day. Those who desire to live frugally have to learn to balance the exchange of time and money. For example, does the savings you get from couponing merit the amount of time it took you to clip the coupons and find the specific item? Do break-and-bake cookies cost memories with your kids and grandkids? Will air travel pay for itself in the amount of time it saves you to get from point A to point B?
How much is your time worth?
Closely related to time as a currency is energy or effort. Early on in civilization, people were less dependent on merchants for their basic needs. They grew and raised (or hunted) their own food, built their own homes and sewed their own clothes. Those methods cost both time and energy but required very little money. As history continued, people sought ways to meet their needs in less time because they were employed away from the home front. Gardens were replaced with markets and hand-carved furniture with factory renditions. Milk was delivered, gifts were purchased instead of made and recipes were instant