We have a number of items which are sold based on a formula of unit cost + 15%. Our items are sorted into Item Discount Groups for the purposes of pricing. For example, if Item Number 3-111 is part of Item Discount Group ZZZ, we can easily assign it 15% off the unit price. All "ZZZ" group items will get this 15% discount. However, how do we perform the same function but instead of discounting off from Unit Price, we add 15% to the Unit Cost of the price?