Online Order Machine

I am trying to figure out how CLWK pays out for the Online Orders. I can't find a rubric for why it pays a certain amount for different things.

I sold 1700 Mushroom Soup (2hour) for 3060 coins.

I sold 1500 Corn Soup (20min) for 2700 coins.

I sold 400 Broccoli Soup (2min) for 720 coins. 

This comes out to 1.8 coins per serving. You also get 500 xp for any order regardless of the quantity.

So far every soup yields 1.8 coins per serving regardless of how long it takes to cook. (Other than Healing Potion)  Other items (sandwiches, desserts etc seem to give a different amount per serving.