Jason gets a gold-star
One thing I will point out is the expense of getting started.... A simple RDA/RTA/RBA and a Mech Mod can be fairly cheap, but as Jason pointed out, two or four GOOD batteries, a few spools of Kanthal, wick material, cutters, torch (an old lighter will do in a pinch), cutters, ceramic tweezers, AND OHM METER will add to that cost rather quickly.
You can do it for under $100, but I always want to point out the initial expense... And, I stress "initial", because after you buy all this stuff, you'll only have to keep yourself stocked (a little here, little there)...