I don’t know where you get your figures from. I buy about three tanks year (£15), one coil a week (£1.32 x 52 = £68.64) and 75 bottles of liquid @ £2.50 (= £187.5). In addition I might buy three replacement batteries a year, costing £40. The total comes to £311.14. Adding a little for chargers etc brings it up to £330 a year tops. Compared with the cost of my previous £5,000-a-year tobacco habit (one ten-pack carton a week), this is almost negligible.