[ShopVac]

Taking all your base items out of this, and assuming you have the same amount of electricity costs to heat a griddle vs heating the oil, and the same labor amount to cut fries vs cutting home fries, the only additional costs would be the oil used to cook these. As you have about a table spoon to cook the home fries, vs the entire fryer that would need changed out constantly (every couple days to weekly).

Now, if they heat the griddle for everything else, home fries can just be added. So I'd assume an extra cost for heating the fryer.

Then, we're talking the possibility of them cutting a potato for the home fries, and using a pre-made bag for the french fries, which I would assume has an additional cost.

The fact you got french fries with breakfast is the real issue here. Who does that? Your a hooligan and should probably seek help. They're probably trying to teach you a lesson...