This paper is an early attempt to explore the cost dynamics associated with blockchain implementation in supply chain. A system dynamic model is developed for that purpose that captures the theoretical value of blockchain implementation resulting from the accumulated costs and benefits encountered by supply chains over time. This model explores the promise of blockchain technology in supply chain logistics by synthesizing research from both fields to build a theoretical framework for understanding what factors drive costs and benefits of blockchain implementation. The main input elements in this model are the supply chain network size, the size of the supply chain entity seeking to implement blockchain information systems, and the level of process digitization desired. These inputs proliferate into qualitative cost and benefit relationships supported by existing research. These individual relationships are extrapolated into a quantitative format for modeling and synthesis. Results show that, the theoretical benefits of blockchain implementation generally grow in accordance with increases in digitization levels, firm size or network size. Network effects are identified as an underlying phenomenon in this relationship. The paper presents a novel framework for considering the relationships that underlie cost and benefit opportunities and challenges of blockchain in supply chains. Furthermore, important practical recommendations are proposed to help supply chain managers in some critical decisions necessary for successful and feasible blockchain implementation. The primary contribution of this work is a broad framework for understanding the functions underlying the often-touted benefits of blockchain technology in supply chains. These findings and synthesis serve to inform design and implementation considerations from a cost/benefit perspective and as a starting point for additional research.