Why are you pulling random numbers out of your ass?
If a worker makes 60 burgers in an hour and they are paid $20/hr then that adds 33 cents to the price of a burger that assembles itself. If they are paid $50/hr then 83 cents.
Except it is hard to imagine there to be enough demand all the time to sustain this for every hour they work, and even in case there is, they would be happy busy making so many burgers for maybe eight hours in a row each day. And let's not ignore that making food is also not the only work for those working in a restaurant.
I mean, if the customers won't mind, and agreed to pay much more, the wages could also grow much more.