It's all about money. Governments are losing a fortune on tobacco revenue and can't sustain the loss so they'll find a way of getting some of it back from smoking's replacement -
vaping. It won't take too long to convince the general public that it's somehow bad - I mean "it looks a bit like smoking so it's not allowed", and "we haven't approved the ingredients" is the best they can come up with so far...and people are actually buying it?? Wasn't smoking alienated cos of passive smoking? Has anyone heard of a
vaping death? They'll regulate it so highly that only their well funded Big Pharmaceutical pals can sell it, and they'll make sure it's as ineffective as patches and gum so that you'll go back to funding their nice offices by buying Marlboro again.
In the words of Month Python...it makes me seethe!
Sorry I went on a bit of a rant there, to get back to your question....nicotine liquid has a shelf life of maybe two years. But, as far as I can find out, there's no reason it won't last maybe ten years if kept in brown glass bottles in the freezer (fill them to the top tho as air can react). So get into mixing your own and stock up on base nic. The other ingredients are widely used in food products so I don't really see them regulating them too much. I believe ejuice will go off far quicker than nicotine liquid.
edit..maybe Canada has already taxed base nic loquid, as I just re-read your post. There must be a way to get some somehow?