We study optimal pricing and order policies in supply chain management of fashion products (e.g., a fashion apparel category) with consideration of product returns between supply chain partners (B2B). In order to study channel performance and optimal policies, two stochastic models for centralized channel and decentralized channel are, respectively, developed to handle new fashion and off-season product sales. In the centralized channel, closed-form solutions for optimal order and pricing decisions are proposed for new fashion products. Further, in a decentralized channel, the Stackelberg game model is proposed to derive the optimal Stackelberg equilibrium solution, and then a buy-back contract is designed to coordinate the channel. We also perform parameter analysis on performance of the two channel models. Numerical analysis is finally presented to validate our theoretical results and compare channel performances.