Remember initial investment? This only gets subtracted as you go along, if your spending less. Otherwise.....look at your initial investment as the "begin hobby price" and choosing to improve your health.
Doing the math: I was spending 35 bucks per week and total is of course 140.00 per month. I now spend around 140.00 per month on supplies, be it whatever.
5ml per day x 7 days at .90ml per average = roughly 30 per week on juice = 120.00 per month.
Occasional 20 pack of carts = 20.00 per month. One carto lasts anywhere from 5-10 days.
OR! Purchase of C tank atty blister pack at 25.00 per month. Atty lasts between 10-30 days. (let's say)
Total here is 120-140 per month. Sometimes we'll have all the cartos we need for 60 days. A blister pack of new C atties will soon run you 25.00, while all five may last you a couple of months. It's a staggered timeline based on your supplies and needs. Last month was just juice, this month was just carts etc.
Occasionally you'll want a new batt, latest kit, or try a new delivery device on the market. This is where it becomes a hobby or want. (though new batt will be required from time to time) it becomes like anything else. New laptop or vape kit? New smart phone or mod device? Flowers and chocolates for companion or latest tank set up? (be prepared to explain) Five topping pizza or Romain noodles etc.........
Just have fun with it, and know you made the right choice for health. Price does not necessarily matter, give or take. Soon you'll be having fun like the rest of us, while giving long and drawn out explanations and such......