I am think of getting these from US since I am used to getting stuff shipped to me here. I am making a comparison from building my own ego twist as opposed to buying the kit. Let's see what do I need..
Joyetech 1000mah battery
clearonizer (how many do I need/how often these need changing)
charger
liquid
Did I miss something out?
You really need two batteries, even if one isn't a Twist to save money. Otherwise you won't have anything to vape while the first battery is charging.
The number of clearomizers is tricky - there are many variables, such as filling one up with juice, then not liking the juice and having to dump it out and start over. They are also famous for having inconsistent quality, name brands or not. Personally, I like them, but with inconsistency in mind, I buy 5 or 6 at a time. I get the cheap disposable ones (not the kind that you can change heads on). How long they last varies too. I usually have 3 or 4 filled with different flavors that I rotate; I mostly use my carto tanks though, so those clearos can last months. If I was just vaping one, everyday, I would roughly guess it would last a week? It's really hard to say. I've had good luck with them, but I've read posts where people have had them burn out in a couple of days.