Im getting close to 20 years worth. Not sure I want to buy more than that because at that point the quality of the tinned tobacco may have already peaked. I don't know that, but thats what I'm going with.
I don't believe it will ever be made illegal since hopefully the government is starting to come around to the fact that prohibition doesn't work. Its taken them 100 or so years to figure that out, but at least it's trending in that direction.
Bingo! Smoking is addictive and can become an addiction, is not healthy for you and can kill you. And, I love smoking.
Prohibitions are counterproductive. Death by a thousand cuts, information that makes smoking less glamorous, pictures of rotting teeth and blackened lungs, all combine to effectively cut down on the desirability of smoking.
The cost to the US economy of tens of billions of dollars in lost productivity and increased healthcare costs is a reason why private industries favor smoking going away. Tax revenues don't make up for the economic cost of smoking. Smoking can severely impact your usefulness as a cog in the economic wheel.
All that said, a flat out ban, the fevered dream of paranoids here, there, and everywhere, is highly unlikely because it's unnecessary. Smoking is waning and will continue to do so. Make it less desirable, less convenient, less available, more expensive, in little steps, and it will eventually be highly marginalized if not eradicated. Less economic cost, more healthy cogs. What more could you ask for?
A 20 year supply is a good goal. Tobaccos can last much longer than that before they peak and croak out, but 20 years is a good age, by and large. After that, the results get dodgy. Tins fail, tobaccos fade, shit happens.