Example of a 'variable option' that depends on a quantity of
items with a single (aka the same) Product ID number regardless of the
options selected for the items within a customer's checkout basket / cart.
The token %%prodID-*%% is a wildcard, the modifier * means match
all products with this same product ID no matter what the options or modifier are.
If combined with the modifier style variable options then this discounting will match up with
all cart contents when these products and any combination of options are added to the cart.