The cost of protein powder can vary widely depending on the brand, source of protein, and ingredients included. Some of the most affordable protein powders include whey concentrate and soy protein, which are widely available and less expensive than some of the specialty protein powders like casein or pea protein. When choosing a protein powder, it is important to consider not only the cost but also the quality of the protein, the taste and texture, and any additional ingredients or additives that may be included. You may also want to look for protein powders that have been certified by a reputable third-party organization to ensure that they meet certain standards for quality and purity. To get the best value for money, it may be helpful to compare the protein content, serving size, and cost per serving of different protein powders to find the one that best meets your needs.