||The subject of the thesis is the behaviour of buyers in the first days after price liberalization when prices of most goods and services in the economy change overnight and, moreover, the prices of a given good or service are different in different stores, while before the liberalization, the price was the same everywhere. First, the thesis describes the situation at the consumer market in the time of the liberalization. Next, the thesis provides an overview of those areas of economics, psychology and "consumer research" whose subject of inquiry is close to the task solved by a consumer looking for a low price in a market with prices unknown to that consumer. After that, three rules are suggested which might be used by actual buyers when looking for a low price in an unknown market: Adaptive Rule, Bargain Rule and Improvement Rule. An experiment is then described on whose results the three rules are tested. Before the tsting itself, there is a discussion of the difficulties brought about by the fact that a nonlinear version of the probit technique has to be used and that the values of the rules` parameters have to be estimeated by numerical methods. it turnes out that on the basis of the data from the experiment, it is not possible to earmark one of the rules as closest to reality.