Each of these metals is of different value. They are, nonetheless, included together and considered of equal importance. For, this is “an offering of the heart,” regarding which it is stated: Whether one gives more or less, it is meaningless, as long as his thoughts are focused for (the honor of) Heaven.” (Berachos 5b). How much one gives is not important. Rather, it is the motivation for his donation which is of critical value. Thus, gold, silver, and copper can be perceived equally.