Cost is a factor that explains the value that learners place on a task based on a cost-benefit analysis, a concept that originated in expectancy-value theory. In recent years, cost has gained attention as an explanatory factor for maladaptive motivation and has been studied in a variety of educational contexts. However, the existing research on cost has several limitations. First, empirical studies exploring the role of cost have accumulated, but the results vary depending on the individual and environmental context, which makes it difficult to generalize the concept or apply it practically. Second, the method of cost differ across the studies, resulting in inconsistent findings regarding the relationship between cost and learning outcomes, which limits the elaboration of the theoretical framework. Third, there is a relative lack of intervention studies aimed at effectively reducing cost, and practical applications in educational settings remain limited. Therefore, this study analyzes the current state of the literature on cost and discusses future research directions for theoretical understanding and practical application.