I added ingredients and their costs into the Ingredient List as required. However, the cost for the recipe isn't being calculated correctly.
This happens when you don't have anything within the "Is Equal To Weight" fields within the Nutrition Facts tab of the Ingredient List.
When adding your own ingredients it is not enough to just populate the Cost fields in the More Info tab of the Ingredient List. Type in an amount and unit for the "Is Equal To Weight" fields. The other fields (calories, etc.) can remain blank.