Enter your agreed discount in the Discount % box and click Apply - this applies to every product you add, including ones added or increased afterward.
Add what you need with quantities. Some products also show alternative options - a lower-tier (simpler, lower-cost) or higher-tier (more capable) model in the same family, if worth considering.
Change the Discount % field to whatever you want to offer them (e.g. 5%) and click Apply again. Then Copy to Clipboard, Print or Email Me at that rate.