The value of money is best determined by the purchasing power. This means that the value of money is determined by the amount of goods or services that can be purchased with it. In other words, the purchasing power of money is the amount of goods or services that can be acquired with a unit of currency. For instance, if the purchasing power of a currency is high, people can buy more goods or services with a smaller amount of that currency. Therefore, the value of money is best determined by the amount of goods or services that can be purchased with it, which is known as the purchasing power.