Based on its share in the total agricultural and food production, as well as on its significance with respect to nutrition and costs of life of the population, the reproduction vertical line of oil industry represents one of the most significant segments of agricultural market. Economic relations between raw material and final phases in agro-industrial reproductive vertical lines are very complex. The analysis of those complex inter-phase relationships, as well as the change management mechanism at the agricultural market may rely on specific relations among prices in agriculture to a great extent. Being the most complex market phenomenon, prices are the indicator of market conditions and the instrument of market functions at the same time, and thus the indicator of trends that are difficult to predict at the total agricultural market. Therefore, this paper takes into account transition changes and the dynamics of raw materials and final products production on one hand, and the changes of horizontal and vertical parities of prices of the most important products in the reproduction vertical line of oil industry, on the other. In view of arriving at more objective conclusion on tendencies and certain regularities in the observed trends and relations, the analysis shall take into account the period of twenty years before and 'the post-transitio' period, and/or the last decade of the previous and the first decade of this century.