What is the Working Logic of Price Breaks?

Summary:

We have a BPA defined with 6 price break as follow.

quantity - 1, Price Break - 54.50;

quantity - 2, Price Break - 50.25;

quantity - 3, Price Break - 47.83;

quantity - 4, Price Break - 46.12;

quantity - 5, Price Break - 48.9;

quantity - 6, Price Break - 48.41;

We have created a local catalog and have linked this BPA. When we try to create a requisition for the item from the SSP page we see that if quantity is > 6 then price taken is 46.12. We want to understand why this is so and how the system will calculate the price if quantity is more than the specified quantity in the price break?