This study attempts to transition elementary economic education into a value-oriented economic citizenship education inherent to social studies. Based on the discourse of ‘incommensurability’, it empirically analyzes the cognitive conflicts and critical thinking processes that elementary students experience between efficiency-oriented market logic and fairness-oriented non-market norms. For this purpose, a justice-oriented economic curriculum was designed and implemented for fourth-grade students at S Elementary School in Ulsan. The curriculum focused on the amusement park ‘Magic Pass’ system and the commodification of everyday goods. Data were collected through classroom video transcripts, student worksheets, and reflection journals, and were qualitatively analyzed. The findings are as follows. First, learners initially demonstrated a mainstream economic ‘market logic’ justifying benefits based on monetary payment. However, through the discussion process, they expressed emotional backlash and a sense of relative deprivation regarding the erosion of the egalitarian community norm of a ‘first-come, first-served’. Second, students attempted to draw boundaries around different values through categorization activities of everyday items. They recognized that domains such as effort and achievement, care and relationships, and life and human rights constitute inestimable ‘personal property’ and are incommensurable. Based on these findings, this study proposes an expansion of social studies economic education. Economic education must move beyond merely ‘cultivating rational consumers’, It should nurture economic citizens equipped with the critical thinking skills to discern inestimable values amidst the sweeping tide of indiscriminate commodification.