This article offers a constitutional and institutional analysis of emergency price regulation through a structural comparison of two historically distinct interventions: the Edict on Maximum Prices issued by Emperor Diocletian in 301 CE and the system of official price controls and rationing introduced during martial law in the Polish People’s Republic (1981-1983). Rather than treating these episodes as isolated historical curiosities, the study conceptualizes them as manifestations of a recurring pattern of crisis governance. The central thesis is that emergency price regulation represents a form of normative substitution in which political authority attempts to replace decentralized coordination mechanisms with administrative command. Drawing on institutional economics, constitutional theory of emergency powers, and legal theory of systemic complexity, the article introduces the concept of “Regulatory Utopia” as an analytical framework for understanding structural misalignment between legal normativity and economic coordination. The findings demonstrate that while emergency intervention may temporarily stabilise political order, suppression of the informational function of prices generates informal adaptation, institutional misalignment, and long-term erosion of legitimacy. The comparative perspective reveals structural recurrence across divergent constitutional orders and highlights the limits of normative power in governing complex economic systems during crisis.