Isn't the profit calculation must be done with NET profit instead of Gross profit? Products maybe give more profit according to your calculation but the materials used in the process also more expensive. Hence reducing your 'actual' profit.

Very simple thing is the blueberry and raspberry muffin. In your calculation, blueberry muffin seems to appear more profitable compared to raspberry which is only Revenue / Time. But if you calculate it like, (Revenue - Capital) / Time = $/min. The raspberry is giving more $/min because the margin is greater (cheaper to produce). Just a thought of mine. What do you think?

Assuming 38min/muffin 1. Revenue / Time Blueberry: 226.8 / 38 = 5.9