Lemme see....I started out with a 901. Then went to the 801. Then to the kissbox. Then to the Screwdriver (Trog's, not the chinese knockoff), then to the stick, then to the prodigy, then the witch's stick, then the fistpack. Got a V2 on the classifieds that's NEVER worked right. Spent more in sampling juices before settling on the cola for an all-day'er. Spent some more on DIY supplies. Stocked up on attys, then moved on to cartos. I've probably spent around $1000 on gear alone in the year & 3/4 I've been vaping....probably wasted around 250-300 on juices I'll NEVER vape again.
Right now, I average a week-10 days on a carto, but have some that have lasted longer (the one I'm on right now has just hit 1 month) and some that lasted less (one drew funny and tasted like *** right outta the package) - that I ended up tossing after 2 days.
I'm vaping around 50ml per month, down from 60ml, as I find I'm not hitting the vape quite as often....
Sooooo - around $12.50/month in liquids (50ml*.25/ml average) and $5.00/month in cartos (go through an average of 3/month at $1.60 per carto)....so I'm vaping for around $20.00 a month.
with Cigs at what....$8.00/pack around here now???? - and I used to average 4 packs a week (ok, I was a light smoker, so sue me

), I'd be spending $32.00/week, or $128.00/month. One hellof a savings, I'd say