How to derive the Pricing in Service Logistics based on the quantity on the debrief lines

Summary:

For one of our client, we need to provide rebates based on the used oil which is picked up from their customers according to the Market Price which changes month on month.

For Example: We have a Market price (A) = 0.355 for Item1 (for the month of July)

Based on the qty of item received from the customer they have to provide a rebate.

Rebate Calculation:

For the Rebate level (ex: Rebate Level 24X > 20k which refers to the quantity received greater than 20k pounds), they have defined Min market price range (B) = 0.34 and Max market price range (C) = 0.3900

So, in this example, Since