Tiered pricing

We have a tiered pricing structure with line level adjustments but looking to move to an order level adjustment.

In the current setup, the price is setup for different quantities. On the order, for the same item, multiple lines are entered depending on scheduled pick date. Based on the quantity on each line, price is assigned.

New requirement is to reprice all lines and consider the total quantity of the item on the order and then assign the price. Look at the difference in the screenshot below.

The left said is what we have and right side is what we need.