I'm not sure what your point is. You've invented a premise I didn't suggest, about the lack of minimum wage laws and $0 / hr.
If someone is going to reference the US minimum wage, pretending that it matters for the Big Mac context, then it's quite relevant what percentage of the labor force is actually earning the minimum wage. Today that number is exceptionally low and it's trivial for most people in the bottom labor tier to earn far more than minimum wage.
About the only places still commonly paying minimum wage, are small mom & pop businesses in the middle of nowhere (ie places entirely devoid of competition from the previously mentioned big businesses). Independent convenience stores run by Joe and Susie Shop Owner in Buckhannon West Virginia, jobs held by local teenagers that can't drive 60 minutes to the nearest Walmart (except of course even Buckhannon has a Walmart Supercenter; a town in the middle of nowhere with 5,000 people).
The biggest entry-level US employers - which hoover up labor anywhere they can get it - are all paying far more than the minimum wage (along with other now standard benefits like health insurance, which is very expensive and not included in the pay figures).