Firstly, you're comparing the 32" not the 27".
In the US - which is LTTs main audience, and the pricing they use for everything, and who they're talking about when they say "cheapest" the 27" AOC has been 279 for its ENTIRE life, and dropped in price to the 250 shown in the video Sep 20th.
Conversely, the 27" Samsung cheapest was 300, and averaged at 340 until Sep 23rd. Both price drops happening after the content was filmed. Samsung dropped to 279, ie; AOCs launch price.
So.... historically, in the US, the Samsung has never been cheaper than the AOC.
Because you can't buy from Amazon.com instead of Amazon.ca? When I VPN there it states "ships to canada" so you're paying what, $32 USD in shipping, and at most another $37.5 in sales tax depending on province, and I'm pretty sure you don't pay duty charges from the US for computer goods (though I could be wrong) so the total is still 40 canadian cheaper than the Samsung.