I think the custom option is what you will need. There are so many ways in BC to modify a price.
Years ago, I created a form which, when run, created a sales line for the customer in question for every active item. I filled the quantity field with 1 and showed the result as Item, Quantity, Price. Back in NAV days, the user could then copy and paste to Excel.
That done, the complaint arose that it did not show volume discount tiers in sales pricing. So, I had to now loop over every sales price qty level to create a new sales line with the quantity from sales pricing.
The funny part was, even then it was not "correct". Basically, over the years so many different setups (sales price, sales discount, invoice discount) had been created that there was no way to give the customer a complete, understandable price list.
The joy of sales not wanting any restrictions on the creativity they can offer on pricing yet without having to understand how one setup interacted with another.