Edge computing systems have emerged to facilitate real-time processing for delay-sensitive tasks in Internet of Things (IoT) Systems. As the volume of generated data and the real-time tasks increase, more pressure on edge servers is created. This eventually reduces the ability of edge servers to meet the processing deadlines for such delay-sensitive tasks, degrading users’ satisfaction and revenues. At some point, scaling up the edge servers’ processing resources might be needed to maintain user satisfaction. However, enterprises need to know if the cost of that scalability will be feasible in generating the required return on the investment and reducing the forgone revenues. This paper introduces a cost-benefit model that values the cost of edge processing resources scalability and the benefit of maintaining user satisfaction. We simulated our cost-benefit model to show its ability to decide whether the scalability will be feasible using different scenarios.