Abstract
The contribution sets simple mathematic models describing and explaining the way of behavior of various types of investors (the private and institutionalized ones). The models come from the cardinal utility theory which is used for explaining the connection between the subjective relationship towards risk and some pathologic phenomenon of finance theory (for example the moral hazard question of institutionalized investors) and takes into account the decision making of both ordinary people and professional investors. A reliable estimate of the economic surroundings where the investment should run contributes significantly to a quality of the particular investment decisions. The article contributes to a quality of the investment decision by the original and primary approach to pricing information that lowers the uncertainty in occurrences of the relevant scenarios of the project’s development. At the conclusion there is shown how the shift of the decision breaking point shapes the amount of the acceptable price of the information.