Replacement batteries for the Alienware 15 R3 can be found from a variety of sources, ranging from brand-new to refurbished. Prices vary depending on the source and condition of the battery but generally range between $50-100 for new or used models. Alternative sources such as online marketplaces may offer cheaper options than retail stores, though it is important to read reviews before making any purchases. Refurbished batteries may also prove to be a cost-effective solution, providing quality performance at a reduced price.