Yes, such a signature exists, but whether or not it's accurate is up to you. The vape expenses in my sig below, also include extra kits bought as gifts for friends (I have no 'converts' yet). Everytime I buy something vape related, I update my sig. As a result, I know exactly how much vaping has cost me in comparison to smoking analogs.
Expenses ARE scary at first, but after 3 or 4 months, it gets better.