<p>Dynamic pricing enables businesses to adjust product or service prices in response to market fluctuations and changing demand. When a product deteriorates over time, implementing a well-designed pricing strategy becomes even more critical. This paper develops a dynamic pricing strategy for non-instantaneous deteriorating items, considering a variable deterioration rate and price adjustment cost, which include both fixed and variable components. In real-world scenarios, the deterioration rate of perishable products evolves throughout the sales period. To reflect this, the study adopts a non-instantaneous deterioration model, assuming an increasing deterioration rate across two successive phases. The problem is first formulated as an optimal control model to determine the optimal pricing strategy, followed by the derivation of a near-optimal solution. Finally, numerical examples illustrate the effectiveness of the proposed approach, and a sensitivity analysis is conducted on key parameters. The findings provide practical insights for industries such as pharmaceuticals and food supply chains, helping managers design more informed and adaptive pricing policies for deteriorating products.</p>