Suppose that off-the-shelf price of a certain management inf

Question

Suppose that off-the-shelf price of a certain management information system (MIS) software product is 50,000 birr and its size is medium. Assuming that in-house developers cost 2,000 birr per programmer-month (including overheads); would it be more cost effective to buy the product or build it. Which elements of the cost are not included in COCOMO estimation model? What additional factors should be considered while making the decision to buy or build the product?