The secondary education system in Tanzania is under scrutiny for its cost-effectiveness and efficiency. A quasi-experimental design was employed to measure cost-effectiveness, comparing different educational interventions across schools in Tanzania. The analysis revealed that certain curriculum reforms led to a $10 increase in student performance per year of intervention with 85% confidence. Quasi-experimental designs offer a robust method for assessing the cost-effectiveness of education systems, providing actionable insights for policy makers. Policy makers should consider implementing similar reforms based on this study's findings to improve educational outcomes efficiently. Secondary Education, Quasi-Experimental Design, Cost-Effectiveness, Education Policy The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.