If we add up the cost of those three cosmetic requisites (i.e., liner, serum, and adhesive) bought separately, that’d be over $100 spent on cosmetics by a long shot. (Popular lash growth serums on the market range from $24.00 to $99.99 a tube. Add on the cost of your favorite eyeliner, and falsie glue, and wham, you’ve just spent dolla-dolla bills.)