I use around 3ml a day, which works out to about 20ml/week or 80ml/month, give or take. I mix my own, but if I were buying, I'd have at least three 30ml bottles stashed for a month. I see you're from Oklahoma. I'm in Tulsa....are you close by? Did you know we have a vendor in Sand Springs? Vapor Kings....and they just opened a store so if you ran low, you could actually go buy some juice from them.