Order the $1.50 cheeseburger from the mymaccas app and remove the meat for a $1.10 deduction. Then order a hamburger for $1.
Now you may be tempted to put the cheese on the cheeseburger into the hamburger but the toasted bun and sauced cheese will be already flavoured and slightly melted so what you really want to be doing is putting the meat from the hamburger into the cheeseburger instead.
Cheapest way to obtain a cheeseburger right now from maccas.
You also get a vegetarian burger too.
Bargain per rules of this site