I downloaded an app on the playstore that calculates my vape expences with my old cigarette expenses. One of my goals with vaping is to save money so i keep track of my expenses and spend less than i did on cigarettes if i want something really bad but it will move me to the "negative" i just wait a little while longer to get it so i guess my budget is anything less than the 7ish dollars a day i was spending on cigarettes