Once you find the kit that works for you, the only cost will be replaceable items (clearos and juice) If you get into advanced stuff and rebuild your own coils and make your own DIY e-liquid...
You will save money. Sometime last year we did a cost analysis amongst the members... I was averaging 2 packs of smokes a day so about £12 x 7... In my first year, while it felt like I was spending copious amounts of money, it averaged out to about £16-18 a week for the year... however, if I were to do it again THIS year, now that I rebuild and make my own e-liquid... I budget myself.....£20 a month (sometimes £40 if I REALLY want something)
I always look for clearane items, mostly buy second hand mods...and only spend on consumables, new batteries, nic base, flavours, wick and wire (I have a sheet of mesh from earlier this year, that I will probably have for another 2 years
)
All together, my first year savings was close to 4k...this year it should be alot more
You just dont notice the savings because you end up like most of us, addicted to new and better possibilities and it becomes a hobby... or you find new things to spend that money on.