Generally states can't. I wonder if what could technically trip you up is the lack of tax stamps. But can you get in trouble for having unstamped cigarettes? I'd think generally no.
The argument for "it shouldn't" could be that it's a federal supplier and/or some sort of RnD exception. Not sure if NIST would even sell to a private buyer.
Much less than it discourages its use. Tobacco lobbies are fighting price increases tooth and nail, they wouldn't if it didn't work. Countries where the price has gone up have seen decreases in on-going consumption and new addictions. Countries where it's cheap (relative to local income) still have high level of smoking (and second-hand smoking).
Or retail at $15 per pack of twenty over-under the counter at your nearest “convenience” store, if it hasn’t been fire bomber over night in Melbourne, thought that seems to have eased off a bit since they arrested that guy.