The article develops a scientific and methodological approach to pricing based on the criterion of the firm (business) value and constructs economic and mathematical models of the optimal price for various conditions. The study is based on the fact that the criterion of business value, the firm should set prices in such a way as to maximize the market value of its entire property complex. For modelling purposes, this value can be determined based on a profitable methodological approach to valuation. That is, the optimal price level can be called one that corresponds to the solution of the optimization problem, where the objective function is the value of the entire property complex of the firm, and the variables are the prices of its products. Price models are based on the fact that according to the income methodological approach, the value of the integral property complex of the firm is defined as the current value of future net cash flow generated by the business that will use this integral property complex. From the standpoint of this criterion, the firm should set prices in such a way as to maximize the market value of its entire property complex. For modelling purposes, this value can be determined based on a profitable methodological approach. That is, the optimal price level can be called one that corresponds to the solution of the optimization problem, where the objective function is the value of the entire property complex of the firm, and the variables are the prices of its products. The author developed a general view of the objective function of this optimization problem for discrete and continuous models of cash flow, as well as approaches to business cash flow modelling depending on the nature of the relationship between demand for products (services) and their price, which is key to price modelling. A number of economic and mathematical price models have been developed for various conditions, which take into account the nature of the relationship between demand and price (including price demand elasticity), the structure of operating costs (primarily semi-fixed and variable parts), the need for investment, cost of capital, risk level and other factors. The application of the developed methodological approach and economic-mathematical models in the practice of pricing will increase the market value of the firm.