Lol...
In Australia whole Shipments of illegal and tax free cigarettes enter our waters and make their way into the bottom counters of convenience stores and Australia, being an island and with a fragile and delicate ecosystem has one of the most potent and vigilante customs and quarantines systems in the world.
There is corruption at all levels including the highest levels and I expect that will also be the case in the US where there will be billions (not millions) of black and grey market dollars to be made. (After all, you guys are so much more corrupt than Aussies

)
Similarly, Western Australia was the first state to make selling vape gear illegal but in enforcing the legislation they only shut down one online vape store.
The FDAs deeming regs and the results on the vape industry in the USA probably won't all pan out as black and white as most people think. There will be angles not anticipated, channels of distribution not presently known, areas in the law that will be exploited to fight the FDAs ruling.
This is all new and unprecedented legal and commercial territory for the U.S. and it is difficult
to predict how it will all unfold.
So long as the government is getting maximum tax revenue for its buck it won't care if the avid veterans and sophisticated vapers like us sneak in packages from China. No way will they commit millions of dollars of resources to sniff out a package of vape gear and nicotine worth $150 unless it is commercially viable to do so.
This is still a doom and gloom scenario but it won't be so cut and dried.
Finally, the FDA is going to have a massive fight on its hands. It doesn't seem to know that Americans have an incredible revolutionary spirit in their blood.