If you are coming to Shenzhen, I will be more than happy to show you what is available in the markets of Shenzhen as regard to electronic cigaretts.
There is one item that I really want to introduce to you.
The cost is around 50 USD as of today in April 2014. It has 2 cartridges included, and it is good for 400 vapors, and if you want more, you need to buy more cartridges which costs you 2 USD each cartridge. There are 14 different flavors and 11mg nicotine in the cartridges, and there are 4 different colors available for the overall look and package. The battery inside is re-chargable, not disposal.