Goal models in requirement engineering represent stakeholder interests and objectives and help in making decisions when choosing suitable functional requirements based on non- functional requirements. In a competitive environment, stakeholders' requirements may be conflicting and non-functional. Therefore, there is a need for a goal analysis method which offers an alternative design option that can accommodate the conflicting goals of the different inter-dependent actors in a goal model. In this paper, an economic evaluation-based approach known as Cost-Effectiveness Analysis is applied to the selection of an optimum strategy for inter-dependent actors in the i* goal model by balancing the opposing goals reciprocally. The proposed approach involves the optimisation of each objective function based on the interdependency relationships and economic evaluation of their optimal values to prioritise each design option. This helps to facilitate the choice of a cost-effective design option that can accommodate conflicting goals.