This product has the basic price $300 and its own list of discounts:

• -30% for quantity greater or equal 5
• -40% for quantity greater or equal 10

So the module calculates values for the list of discounts applying the percents to the product price $300.

The ability to set discounts using the percentage (the prefix "-%") is a feature added by the module (by default OpenCart allows to set only exact value of discount, equal to the prefix "=").

This product also has option "Size" to demonstrate how the module updates the price depending on the selected options. The module updates product price and the list of calculated discounts every time on option change (accordingly to price modifier of the selected option), the module also updates the product price on quantity change (accordingly to the list of discounts).