Discount display on MM3 Proposal

I have had a number of customers who have questioned what they actually owe based on the calculation when a discount is displayed on Presentation PDF they receive. To clarify, it should be shone as follows:

Materials $1000.00
Services $1000.00
Sub total $2000.00
Discount $ 200.00
Total Due $1800.00

If the discount is not given, the Sub total and Discount lines do not appear. Line items shown in the Presentation PDF should not be a discounted amount (as I think there are now) but a “gross amount” that could be discounted in the above calculation