Ok, what's happening with that last formula is that when I add a set of 10 dvds, I do get the 50% discount, but when I add an additional SINGLE dvd from that same db, it also applies 50% off that single dvd. It's not supposed to! It should only apply the discount to sets of the same dvd. I do understand why it's doing that but I don't understand how to get it to work the way I want it to. It should basically say:
"If there's 10 or more items with a specific column value and the item is unique, then apply discount"
That way another item with the same column value does not get the discount applied unless they order 10 or more of that particular item.
Thanks much for all the help. I do understand it a lot more with all the info you've given me. I would, however, like to avoid having to write the same formula for each item (16x because I have DVD and CD with different discount amount).