At roughly 4-5 packs a week, I was around $30 weekly on analogs. I dropped about $250 a couple years ago on 510 setups, extra batteries, and a bunch of juices to get me and my wife going. I quit cold turkey almost immediately, then after 4-5 days was back on the stink sticks partially and gave up on the e-cigs after a month or so - the mess, maintenance, atty failures, and weak hits I got were all major turn-offs.
Big money loser there.
A few weeks ago one of my buddies got an eGo knockoff for his birthday. I gave it a try and got a lot better vapor and more consistency than I'd ever been able to manage with my 510s, plus the clearomizer really turned me on versus trying to drip or fill those cotton-ball things with liquid. After thinking about it a couple weeks, I dropped another $75 getting a couple fake eGo starter kits for me and the wife and we went from 10-12 grits a day down to 3-4, then to 2-3.
About 10 days in, this is the first analog-free day for both of us. I've spent a total of $225 on the starters plus getting us each (better) backup batteries, a bunch of new clearos (just tried the EVODs today and I'm in love), replacement wicks for the EVODs for when they fail (my top-burning long-wicked POSes died after about 5 tank fills), and a handful of bottles of juice in varying flavors and strengths to try.
I've saved about $20 by cutting my smoking from a half pack to 3-4 cigs a day. So again, a big money loser...so far.
I don't aspire to major mod setups or collecting a bunch of different types of devices - right now the eGo setup works great for me, and as long as it does I should have enough parts to last another 6-8 months, with the exception of vv batteries if (read: when) I'm ready to go that route. So if I can limit my cost to juices and maybe a couple batteries for the foreseeable future, vaping should turn from a loser to a winner money-wise in a couple months. Of course, just by cutting my intake by 4 packs or more of analogs a week would be enough to feel like a winner, regardless of cost.