I don't have an exact accounting, but I can tell you that I'm still using my first and only e-cig hardware, my KR808d-1, and I'm well into uh....140 days or so, I think. My kit cost me $75. My first order was about $150, with the kit, cartos and juice from Nhaler.
A month or so ago, one of my batteries died. It wasn't faulty, it was my doing. I was on break at work talking, and not paying attention as I added drops to a carto...so I put the drops in my battery instead. Duh. So, I spent $18 for a mega manual battery.
I also have an ASSLOAD of drops. There's no need, really, for me to buy new drops as I'm sure I have enough to last most of a year. However, I like trying new flavors and vendors, so I buy a couple bottles or so every week. I also ordered some V4life cartos, because I like the idea of them being labeled. Up until that order, I've mainly been ordering vanilla cartos (since that will pretty much go with any drops I have), and chocolate cartos.
My husband also vapes, but not as heavy as I do, so he uses less supplies than I do.
I also ordered my first mod (a Chuck!!) about a month ago, that was $90 total with the battery sleeve and adaptor.
Really though, I don't much care about the cost. Well, I DO, but not as much as I care about the fact that I'm not smoking analogs anymore.
Of course, being paid weekly helps with my shopping frenzy, and I'm lucky in that hubby and I work at the same place, and we make pretty good money.
If I had to guesstimate, I'd say I've spent about...$700-$800 so far?