Because no market is really a market without home-made food, I added the following functionality.

Under the settings menu there is a Food menu this includes:

• Set Price of Food Serving
  • How much you want one plate of food to cost.
• Unspoil
  • Makes food in the stand's inventory unspoiled + calculates the price for the food.
  • If the food is a group serving the price is (price of one serving * how many servings left in the plate).

The price of food also depends on the quality.
If the quality is nice or very nice it's the default price * 1.2
If great, outstanding or excellent it's * 1.3
If perfect it's * 1.4
otherwise it's the default price.
(any time you add new food to the stand, you need to run the unspoilt command unless you want to sell spoiled food that costs 0§)
Please note this is meant for sims who want to sell home made food in their cart. Food has no price by default + it will be spoiled if left outside.