Important Factors to Consider when Purchasing Wigs for Women A number of factors determine the price of hair wigs. Human hair wigs are among the most costly, though some models are constructed from synthetic materials. Hair lace made from natural hair comb hats are also the most expensive. Although they're usually less costly, they require more maintenance. Hair bobs react differently to humid conditions as well as the weather , and could need to be changed or dyed to appear its best. Because of these factors it is important to consider whether the cost of purchasing a natural human hair bob is worth the extra expense.