Approaching my one year anniversary being completely smoke free!!! WOO HOO!! I have replaced the batteries twice at a cost of 20.00 each for a total of 40.00. I estimate the liquid runs me approximately 10.00 per month...much cheaper than the $144.00 a month that cigarettes would be costing me to buy. Also, I don't have to go outside in the heat of summer or the cold of winter to get my fix....I just sit at my desk. If you're serious about quitting, get one of these....it worked for me!