Globally, breast cancer management is associated with a heavy economic burden, but its impact in Saudi Arabia has not been fully quantified. The aim of this study was to estimate the economic burden of breast cancer management at various disease stages, in Saudi Arabia, from a payer perspective. We conducted a retrospective, multicenter cost of illness study in two governmental healthcare centers from January to December 2018, using the data of 300 patients at different breast cancer stages. A micro-costing, bottom-up method was used, and descriptive and inferential statistics were analyzed. The total estimated cost for treating breast cancer during the study period was $13.345 million USD, with the average cost per patient ranging from $14,249 USD in stage I to $81,489 USD in stage IV (p < 0.001). Medication cost was the main driver of total healthcare spending, followed by hospitalization and diagnostic tests. The cost of targeted therapy drugs represented 67% of the total medication costs, mostly driven by trastuzumab-based regimens. The economic burden of breast cancer management in Saudi Arabia is substantial and increases significantly with disease advancement. Early detection screening programs, evaluating the value of highly expensive interventions, and considering biosimilars, may contribute toward cost savings.