I started off with one of those cheap starter box kits (190 510 batt, charger and 3 carts) at the flea market and a 10 ml bottle for $30, they were running a Christmas special. Later, bought an extra 190 mah battery for when my first battery needed to be charged, $10. Then, I switched to cartos for obvious reasons and learned how to boil them for reuse, $10. When the first battery gave up the ghost for good, upgraded to the eGo 650, $20. Bought a second charger for when the first might go, $8. First batt died and gave my brother the second batt and charger and bought another eGo 650, $20. Since, I had bought 2 more 5 packs of cartos and am waiting on a eGo fast-charger from Liberty Flights, $30. I started last Dec. and this has kept me maintained up until now; $110 in hardware over 5 months.
Juice is a different story, I bought from AVE, LF and FSUSA. Out of all, I mostly like the Pall Mall and Zen Watermelon. Can't really say how much I spent on mostly samples. Being honest though, I usually go back to the flea market to get the Marl Red 18mg. The guy who runs the Vapor Rising there is great, he'll throw in another bottle to try. The Orange was great, the Beer, not so much. If I stuck to one or two flavors, I'd say 30 ml would last me a month, $20. So, I guess that would be $45-$50 a month. YMMV