The profitability of purchase of agricultural, usually expensive machinery, depends first of all on unit price as well as on their quality. To determinate profitability of purchase of agricultural machines there were used price and quality coefficients, and quality was imported to numerical figure. In order to gain it there was used author's method of estimation of agricultural machinery quality. Simulating investigations were conducted on reversible ploughs of different manufacturers. Presented methodology should be helpful in decission process of purchase of new and used machines.