Machine learning (ML) has become extremely important in communications due to the increasing complexity of networks and due to its promises of improved performance, efficiency, security, cost reduction, and customized user experience. In wireless networks, ML is researched and used in several domains, from access networks to core networks and network services. In network security, the promises of machine learning are vast, from preventive measures to detection to response and remediation. However, machine learning requires a huge amount of resources, mainly due to the fact that ML operates on data, and data volumes are consistently rising. In this review article, we explore the aspect of resource consumption of ML techniques used for network security and provide a comprehensive review of the current state of research. Moreover, we propose a taxonomy that can be used to classify the methods through which the resource consumption can be reduced for different ML-based network security implementations. The focus of the study encompasses several key aspects pertaining to resource consumption, including energy, computing, memory, latency, bandwidth, and human resources. These resources are critical in improving the efficiency and optimizing the reliability and sustainability of network security solutions. Furthermore, based on the extensive literature review, we summarize key points regarding optimizing resource consumption in ML-based network security solutions. Finally, the challenges and future research directions for resource-efficient, ML-based network security solutions are outlined to aid in the advancement of research in this area.