I've shipped tons of stuff from here (Canada) to the 'States. Canada Customs won't add any costs if it's leaving Canada, but they'll screw you if you ship stuff in. Doesn't matter what it is, if its value is greater than $500 CDN they'll add tax and import fees, even if you declare it a gift or a return. Then it's up to us Canadians to re-claim the fees. Jerks.
But there's no problem shipping down from Canada.
And if there's a legal problem it's very easy to deal with the RCMP. Because they're a Federal Police Force they can go anywhere in Canada and co-ordinate with any other branch anywhere. And they take things pretty seriously.
With the US dollar worth $1.20 CDN it's a good time to buy. Let us know what happens.