The purpose of this study is to examine the costs of replacing high school principals. The technique for cost estimation used is the 'ingredients method' and is based on the economic principle of opportunity cost. It is the recommended form of cost analysis by experts in the field. Within this study, the ingredients method systematically identifies all the resources required to replace high school principals, and attaches prices to each of those ingredients. The systematic nature of the method allows for costs to be measured and compared across studies. Data were obtained from executive-level human resource management across six South Carolina public school districts. Costs of high school replacement varied by district (ranging from $10,413.03 to $51,659.27), with the sample average equating to $23,974.29. The methodology used in this study can be replicated across the globe to estimate the cost of replacing school leaders.