Rational pricing strategy is one of the most important problems in economy. Pricing comprises a number of subtasks including product price formation, existing price adjustment and analysis of deviations in wholesale customer behaviour. The objective of this study is to create an intelligent technologies based decision support system for solving the above tasks, which is based on finding the hidden regularities among the sets of time-series. For that purpose, a number of Data Mining technologies are used. To store the data mined, concepts of classes and behaviour profiles are introduced. Behaviour profiles are employed as the input data of recommendation and decision making module.