Suppose Bob is wealthy. He might exchange his entire life savings for a litre of water, which Alice owns, if he is dying of thirst. However, if only 1 litre of water is available between the two, then no amount of money or other products might represent sufficient value to Alice, to share or sell her water to Bob. She may believe that she needs the water for her own survival. The value of the water to each, in this extreme example, is dependant on its scarcity and their needs. The price to be paid for the water, is dependent on Alice’s value system and the value of what Bob is willing to exchange. If Alice considers that Bob’s entire life savings is worth less than the litre of water, then she will not sell it. It may be that Alice has an abundance of water and will sell for less than Bob’s fortune, but Bob might still be prepared to exchange everything for the water. In theorising about the value of products, people have often been unable to resolve the apparent paradox of why diamonds generally cost more than water. Diamonds are almost useless, while water is essential. There is no paradox, but the question is incorrectly framed. All water is never exchanged for all diamonds, but discrete quantities of each commodity are exchanged for other goods. As water is normally abundant, people often have more than enough, and are unwilling to pay much for specific quantities of it. However, diamonds are rare and frequently highly desired for their ornamental value. Consequently some people are prepared to pay highly for a diamond. Scarcity is a fact of existence. Even in the super abundant Garden of Eden, each individual has only one body. He will place a high value on that body. If he were able to avail of a second body, then he might risk his initial body far more than if the second one were not available. Each individual controls a limited amount of resources. If some of his needs are already met, then he will pay less for additional products which meet those needs. He will spend his limited resources on other products which will satisfy other, unsatisfied needs. Value is a subjective judgement, which is unique to each person. An individual who desires more sophisticated products, must produce goods which satisfy great needs, in order to attain his goals. It may be that an onlooker may judge that Bob is crazy when he spends vast sums acquiring unique works of art, but each individual has unique desires and value judgements. In a free society, only people who satisfy great needs by increasing the abundance of needed goods, can afford to consume great amounts. Price and value are not the same. When Paul sells a potato to Peter for 2 carrots, it is both supplied and demanded at the same time. Paul supplies the potato and Peter demands the potato. Price is determined at the moment of exchange and is determined by the relative valuations of both parties to the 2 products being exchanged. In a modern economy, 1 of these products is usually money. Despite some unique characteristics, money is not of stable value and it fluctuates just like any other commodity. Certain things may never be exchanged or sold, such as the love of another, so they can never be priced, but they are still valued.