Spare parts are critical to delivery of after-sales service, and component obsolescence can affect spare parts replenishment, which leads to longer product downtime and reduces product availability. In practice, life time purchase is used widely to deal with part obsolescence; yet its impact on suply chain management has not been well studied in the literature. This paper proposes a dynamic suply chain game model which captures product sales and after-sales service simultaneously. The interactions between the optimal decisions for product order quantity, pricing, and spare parts life time purchase quantity are analyzed, and the impacts of warranty and part reacquisition cost on the equilibrium outcome and the suplier's profit are discussed. The results show that when the reacquisition cost is low, the suplier should offer long waranty while reducing the life time buy quantity to maximize the benefit of improved product availability. In the meantime, the technical standard for spare parts quantity should be reduced properly. When the reacquisition cost is high, the suplier is encouraged to reduce the waranty period and to purchase more spare parts to better control the cost of replenishing the obsolete parts. Then, the technical standard for spare parts quantity can also be set higher.