I used to smoke 1.5 packs a day, which is almost $70/week. I ended that back mid-July. If I hadn't, it would have cost something like $1000 to keep smoking till today, which is a disturbing thought. So far, vaping has cost around $450, with about half on diy juice supplies, rest on two evods, two protanks, five drip tips, four batteries w/chargers, lots and lots of replacement heads, juice I bought before getting into diy. Obv these are not the latest and most expensive gadgets, but they work well for me and that's enough.
I have almost everything needed to keep vaping till July '14; might spend $50 more on some extra flavors, extra heads, a drip tip or two, but that's about it. To do some more (depressing) math, if I hadn't quit, smoking would have cost $3600+ between July '13 and July '14. Vaping is a HUGE savings.