Abstract- Selling price and purchase cost typically vary with economic conditions in today’s competitive markets. For a business to be profitable, both the selling price and the purchasing cost are essential. As a result, I expand the inventory model Teng and Yang (2004) established in this study to incorporate the ability for both the selling price and the purchasing cost to fluctuate over the course of a defined time horizon between replenishment cycles. The goal is to determine the best pricing strategy and replenishment schedule in order to maximise profit. The existence, uniqueness, and global optimality of the suggested solution are guaranteed by the conditions that lead to a maximising solution. Some theoretical results and an effective approach for solving the problem are offered. Finally,numerical examples for illustration and sensitivity analysis for managerial decision making arealso performed.