I mean, say, you want a really nice camera, or a drone, or maybe a gaming laptop, and since those things are made in China, they are too expensive to buy right now in the US, since tariffs are over 100%. So you just go to Canada, buy the thing, unpack it from the packaging, and pretend like its just personal items. Just like a smartphone.
AFIAK, border agents usually don’t ask if you bought your phone in the US or from outside, they shouldn’t ask about other personal electronics, right?
This work between certain states. For instance, you can drive into Oregon and shop with no sales tax then return to California or Washington with your goods.
Liquor is also much cheaper in some states than others—you can really stock up if you are already driving through a state.
Fireworks are legal in New Hampshire but not Massachusetts. The MA police will stake out NH firework shops near the border before July 4 and pull over MA cars they see loading up once they cross back into the state…