The interest related to costs and their calculation is not limited to determining selling prices, it is particularly moving towards mastery and reduce costs without diminishing the attractiveness of the product. In the market economy frame is important to know how competitors manage to master their costs, but at the same time, and which is the way how the products sold by entity are added in chain costs to users, which causes its costs and performance by them. Action problem on the cost has a very wide scope. First must to be seen cost is determined at what level, in order to know how to act on it. Also, the computing manner can affect how you act on costs. From the technical point of view the managers can act upon costs relying on laws they follow, laws imposed on their behavior.