Economic entities with dominant position in the implementation of its product counterparties using various approaches to pricing, often the price of goods is formed not on the basis of its costs and necessary for the continued functioning of the company profits. These actions lead to the fact that prices for the same goods are different for customers only exceptions are the conditions of a public contract, according to which the prices of goods, works and services are set the same for all consumers. The result of such actions on the wholesale market, will be the difference between retail prices in retail chains, not to mention the level of purchase prices for budget organizations, as an example in primary care from the manufacturer may be pricing, based on the technological conditions of the sale of goods, when the actual complete list of registered costs. Consequently, the entity - a monopolist in the sale of goods should be justified, the result of some factors is the unequal position of some suppliers over others.Due to the significant number of antitrust authorities to cancel the decision in arbitration this article focuses on the development of methodological aspects of the evidence establishing a monopoly economically unjustified different prices for the same goods.