Bread in Finland is about 0.1 usd per slice Low quality cheese is about 8 usd / kg, assuming you need about 20g/portion that’s 0.16 usd. Total is about 36c per portion.
If we assume power consumption of 5kw for the whole operation and power cost of 20c/kWh, that’s 1usd/h
Assuming sales of 60 units per hour -one per minute, thats 60 usd of revenue per hour and 22.6 usd of non labor cost, it leaves 37.4e for labor, taxes, permits, tools, fuel.
It’s at least only feasible in high volume locations.