if you plan to be away from "civilization" for an extended length of time I would say to order twice what you think you will need. Attys/cartos are hit and miss. you could end up having a streak of bad luck. For planning purposes I consider the life of a carto to be approximately 20 -30 ml of
juice or 3-5 days (I'm a heavy vaper). Attys I say one to two weeks, depending on"luck". Batteries... order enough to have two to three fully charged at any given time, counting the battery(ies) on the charger. Chargers, get two. As far as
eliquid, I try to keep at least 300 ml of my go to vapes available at any given time.
These are just my personal thoughts on maintaining an adequate supply, other people will have their own stockage levels and recommendations, your mileage may vary