this gets quite a bit more complicated, and will require some additional cart columns to make work.
there are a couple of points i need clarification on:
1) "I want the user to call in orders of 2 cases or more."
does this mean 2 cases for the entire cart?
or s cases for each item?
can a case be comprised of 6 50ml cartridges, 3 250ml cartridges, and 3 500ml cartridges?
2) 12 items is the max the user can order. When 12 is ordered, they get the case price outlined above.
this is contradictory to my understanding of the first point, from your wording in the first point, i understood it as meaning up to 23 of any one item could be added to the cart, the first 12 items would be given the case price, the second 11 the individual price.
Is 12 items the cut off or 23?