Models of conflict in networks provide insights into applications ranging from epidemiology to guerilla warfare. Barabási, Albert, and Jeong modeled selective attacks on networks in which an attacker targets high-order nodes to destroy connectivity; Nagaraja and Anderson extended this to iterated attacks where the attacker and defender take turns removing and rebuilding nodes and edges according to given strategies. We extend the iterative model by introducing the cost required to perform network operations. This gives a much finer granularity than previous models, whether we are interested in network resilience against random failures or intentional attacks. We empirically study how to design more effective attacks and/or defenses through intensive simulation on several well-known network topologies, including the three real-world networks. In particular, an effective defense against many attacks is to add new links connecting low-centrality nodes to maintain the overall balance of network centrality.