In the Prices block there is one tab per portion type (Meal Prep, and Catering when that module is on). The first row is the default portion (named by Portion Size Default Name, e.g. Normal):

• Meal Prep Price - the current selling price for the default portion.
• Surcharge - an extra amount added when this meal is chosen inside a fixed-price Meal Pack or Meal Plan (a $100 pack of 10 becomes $105 with a $5 surcharge). Meals with a surcharge are never auto-chosen or randomly selected.
• Regular Price - an optional higher "was" price shown struck-through to customers. Saving fails with "The selling price should be less than the regular price" if it is not higher than the selling price.
• Serving Size - how many people the portion serves (numbers, spaces and hyphens only, e.g. 10 - 20).
• Container - the container type for this portion (shown when container types exist).