@ATLSteve 

"Is this even possible with QB Online?"

Not exactly.  You can add your customer's terms to their customer profile so they are listed on their invoice but it doesn't automatically apply the discount to the line items.  

As a side note, I'm not sure about your industry but that is pretty standard in many.  I was a corporate controller for many years and our companies had over 1,000 vendors with various discounts.  90% of our vendors listed the products at the list price with our specific customer discount listed under 'Terms' on the invoice and it was up to us, as the customer, to take the discount.