The major intention of this study is to reduce the total expenditure of a vapor absorption cooling system (VACS) by developing an optimization model with an alternative working pair LiCl-H2O and compares it with the traditional LiBr-H2O system. Considering the cooling capacity of 50 kW, two working pairs were to compare parametrically at various operating conditions. The model comprises of three parts, viz. a thermodynamic model for the estimation of coefficient of performance, exergetic efficiency, and availability destruction of system components; an economic model for computing expenditure flow rate and capital investing expenditure rate; and the minimization of the total expenditure using genetic algorithm. The parametric study suggests that a LiCl-H2O system performs better from both thermodynamic and expenditure-effective aspects under all working conditions involved in this study. Especially, a low generator temperature produces a noticeable difference. The present global optimization technique assesses the optimal operating temperatures of generator, absorber, condenser, and evaporator. An optimal operating condition provides a system with a 1.20% of decrement in total expenditure rate and 5.39% of reduction in total capital investing expenditure rate using LiCl-H2O solutions with respect to LiBr-H2O solutions. Finally, results derived from this study may assist to designers to choose an alternative working fluid for enhancing the performance of VACS.