The choice of a cost effective lateral-force-resisting system for low-, mid-, and high-rise buildings is challenging. Cost considerations are often primarily based on experience but there is a need for an economic model for comparing lateral-force-resisting systems in concrete buildings. In this investigation a symmetrical twenty Story structure is designed in Seismic Zone 2B by using two different lateral-force-resisting systems, i.e. Dual System without beams (with drop panels & edge beams) & Building Frame system with beams. This structure is designed using four more systems which are done by two other groups. So in the end all six models are compared with respect to cost. This type of investigation can benefit the engineers to quickly select an economical lateral-force-resisting system, thus reducing design time and iterations. The Design is carried out according to ACI 318-05 and UBC 97 using ETABS (for Frame and Shear wall design) and SAFE (for Slab and Foundation Design). SAFE 12 is used for automatic calculation of quantities for Beams, Slabs and Foundation while quantities for Columns and Shear walls are calculated manually. The results of this investigation showed that Moment Resisting System with beams is the most economical lateral-force-resisting system for 20 story structure in seismic zone 2B. It also showed that systems with no beams (with drop panels) are more expensive than systems with beams because more reinforcement is needed in the slabs and drop panels.