If it's about taxes why not impose a tax on ecigs?

Cigarettes are the only form that is relatively easy to tax as they come with a standard dose of non nicotine that needs to ship with them to be accepted. Places that have tried to limit the volume of disposables or ban all nicotine liquid have found that it easy to smuggle a huge amount of value in a small space and/or to add purer nicotine at the last moment.

The tax wouldn't need in the nicotine though but on the devices since that's what we are disposing. How high would the tax need to be to make up for the cost of disposal? Would it be high enough to make smuggling attractive? AFAIK products in Germany (and the EU?) already have a recycling tax built-in for things like plastic packaging and it seems to work. Would this tax need to be that much higher to the point that smuggling is encouraged?