The proliferation of low-cost unmanned aerial systems (UAS) has created an unprecedented cost-exchange asymmetry in modern air defense, exemplified by the expenditure of $3-5 million interceptor missiles against drone threats costing as little as $20,000. This quantitative study conducted a comprehensive cost-effectiveness analysis of counter-UAS (C-UAS) technologies across kinetic, electronic warfare (EW), and directed energy weapon (DEW) domains during the critical period of 2022-2026. Utilizing publicly available datasets from Oryx, SIPRI, and ACLED, combined with defense industry specifications and operational data from the Ukraine conflict, this research developed and applied the Multi-Layered Defense Economics Model (MLDEM) to evaluate 19 distinct C-UAS systems against standardized threat profiles. The analysis employed descriptive statistics, Kruskal-Wallis H-tests, Mann-Whitney U-tests, multi-criteria decision analysis (MCDA), and Monte Carlo simulation with 10,000 iterations to assess cost-effectiveness metrics, technology readiness, and operational sustainability. Results revealed that cost-per-engagement (CPE) varies by more than five orders of magnitude across system categories, ranging from approximately $0.01 for EW systems to $4.75 million for advanced missile interceptors. Statistical analysis demonstrated significant differences between technology categories (H = 13.92, p = 0.0009, ε² = 0.745), with DEW and gun-based kinetic systems achieving consistently favorable cost-exchange ratios against mass drone threats. Hypotheses H1a, H1b, and H2 were supported, indicating that DEW systems achieve CPE ratios below $500 per engagement, gun-based systems below $2,000 per engagement, and multi-layered architectures outperform single-technology solutions. Hypothesis H3, positing a positive correlation between technology readiness level and cost-effectiveness, was not supported (ρ = -0.404, p = 0.086). These findings provide empirical foundations for defense acquisition decisions, demonstrating that economically sustainable C-UAS architectures require a diversified technology portfolio prioritizing directed energy and gun-based effectors over missile systems for high-volume drone defense scenarios.