We have a scenario where the retailer will have campaign prices; eg. Product X price during August is $150, regular price is $200. The campaign price cannot not used together with any other retail discount. If an affiliation discount (regular price - affiliation discount) is lower than the campaign price then it should be used, but the affiliation discount cannot be added on to of the campaign price.

We do not want to have a $50 discount.

(We tried using Trade Agreements (Price Group=Campaign) for the campaign prices but we are unable to exclude the retail discounts from said trade agreement.)