This is what happen when Set Discount Based on Compared at Price is selected:

Enabling a Sales Rule

The following product has a Compared at Price and Price set to the following values:


When a 10% discount is applied to the Compare at price:


Once the sales rule is activated, the discount will be calculated based on the Compare at Price. The calculated discounted price will then replace the value at the Price column:


Disabling a Sales Rule

When a sales rule is disabled, the original price will be restored back to the Price column:


Special Scenarios

If a product does not have a Compare at Price value:


When a 10% discount is applied to the Compare at price:


The price will be calculated based on the Price. The original Price will then be placed into the Compare at Price column:



When the sales rule is disabled, the Compare at Price will then be reset to $0 while the original Price is restored to its respective column: