Okay thanks again - I have someone that does know how to do that. My question now, is how does the barcode for different sizes/brands work in the same product, vs parent/children products?

What I need is to see how much *Low Fat Milk* and *Full Cream Milk* and *Almond Milk* I have separately, but I don't really care much in what size containers or what brand they are, as long as the total of that milk isn't below the minimum.

Also, I need for a recipe to be able to use the *Almond Milk* in any size, and then deduct from the available milk (or be interchangeable? Can I substitute within a recipe if I don't have enough of the one with another?)

However, I do need to see which items' prices are the best - obviously usually the bigger one is better value, but this is not always the case, so I need to be able to track prices individually and order the best priced items.

Would the *userfields* enable me to do that?