Value refers to the worth of an object, individual, or services.

In classical economics, the value of goods is computed based on supply and demand. As supply goes up the value goes down. On the other hand, as demand goes up, the value increases.

The problem with this is that value then is subject to manipulation, since a shortage in supply can be staged via hoarding and demand can also be inflated via marketing strategies. Hence, overpricing and underpricing (done to undercut the competition) occurs.

Furthermore, looking at value purely through supply and demand does not take into account other important factors, like the price of the raw materials used to manufacture goods, intrinsic value of the goods, or the utility derived from the use of that goods/service.

Because of the different ways value can be viewed, described and computed, value should actually be defined by both qualitative and quantitative measures. The quantitative side of value can obviously be measured in dollars (i.e. price of one piece of candy), percentages (i.e. market share), age (i.e. antiques and artifacts), volume, size, etc.
The qualitative side can be measured by different factors. These include brand, physical condition, or emotional/sentimental value. Social, economic, cultural, and environmental factors may also contribute to the assessment of an object’s overall value. Due to the subjectivity inherent in some of the factors that affect the assessment of value, it is not surprising that the value of things (as well as individuals) will vary from person to person.