Ponytail Hairstyles can be made by simply attaching hair clips with pre-made ponytails. These extensions can range from a few dollars to several hundred depending on whether they are real human hair, horse hair, or synthetic. These types of extensions remain wildly popular in 2011. The Jessica Simpson line, for instance, is noted as both popular and relatively inexpensive compared to some hair extension lines. These ponytails come in a large variety, with the wavy, curly, or completely straight extensions being the most popular usually.