BXGY Advanced Logics

so we have our catalog of 50 original products for example. We have added 5 new products. We want: 1. Buy any item at original price, get the 5 of the new product at 50% off price (like an upsell) 2. If we buy the new product on its own, they can get 20% off 3. They can only add one item per original item added (ex. if one regular item, one discount upsell, if two regular items, two discount upsell) 4. If only one regular item added, and two upsell new products also added, the 50% off only apply to cheaper new product, the other new product will show as 20% off