4Scopes is great if the exchange rate is on par with the Canadian $
I've dealt with 4Scopes and shipping is about 2 business days once your order is approved. That was when the Canadian $ was on par with the US $ . But right now with the crappy exchange rate, I'll buy from a Canadian Dealer.
If you're planning to drive down Stateside and buy your scope down there and drive it across the border, your real problem would be if you get caught by Homeland Security. The Canadian Border guys is the least of your problem.
I would suggest to NOT do it unless you want to get more than a rubber glove treatment from the US folks.