Seriously, he manages to spend this entire video pointing out his own obvious mistakes, or saying in the edit how he'll correct them later, but then has to put a correction in the comments about how he drastically underestimated prices that he didn't bother to check, so the final "maybe correct" results aren't even reflected in the video at all. And then he completely speculates on how they might price things and completely neglects the possibility that the pricing at two different restaurants might have anything to do with eachother.
Why even make this? I guess the point about "premium" fast food places selling you bigger portions
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy: