This work presents the application of the COMFAR III software package in development a feasibility study of investment. The application of this program enables an efficient analysis of investment justification and numerous variations of both input and graphic and alphanumeric output data. The methodological basis of economic analysis. used in this software package. https://www.roneverhart.com/ESP-LTD-SD-2-Sammy-Duet-Signature-Model-Electric-Guitar-Black-p20045/