I mean, say, you want a really camera, or a drone, and since those things are made in China, they are too expensive to buy. 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?
Pretty sure this is false in most countries. You are required to disclose purchases and declare values, even for personal use. If they hit a certain thresholds, you’ll have to pay a tax.
Now I’m sure most people just ignore this, because practically they don’t know which items you carried with you and which you purchased. But it isn’t legal.
Last time I crossed back into the US from Canada the agent gave my friend shit because she didn’t have a physical receipt for the purchase she made and couldn’t prove it was worth less than the threshold. Even though I live in a border city I rarely cross because the agents are such assholes