Applying discounts and surcharges
In the Commerce Module, the Discounts tab is where you are able to set up discounts and promotions for orders. These discounts can be configured many ways to create flexible discounts for your customers.
Discounts are comprised of two major sections: the details of the discount, and the discount conditions. The details of the discount specify how the discount is applied, either as a percentage or a fixed amount; when the discount expires, which you can leave blank if it never expires; and how many times the discount should recur for items in an order that are recurring.
To add a new discount, coupon, or gift card, click on the appropriate subtab on the Discounts tab, click the Add a New Discount (or Coupon or Gift Card) button, and fill out the appropriate information. Refer to the inline field help for details on what to enter in each field.
Entering Discount Conditions
Discount conditions specify which customers and items a discount, gift card, or coupon is applied to. You do this by setting up conditions for each discount. You can set as many condition to a discount as needed, and the conditions can specify whether to include or exclude items that match the specified conditions in the discount; which group to apply the discount to; what category of items to apply the discount to; and what items to apply the discount to. Note that to apply a discount to multiple customer groups, you must specify multiple conditions for the discount. Each condition is specific to a group.
Conditions are entered from the Conditions subtab of the Discounts tab. To add a new Condition, click on the Add a New Condition button, the enter the condition name and a brief description of the condition. Click Save, then click Add a New Condition again and fill out the appropriate action, membership group, and catalog information.
To include shipping surcharges for items, you have to enable them in the configuration settings for the Commerce Module. Do this in Green > Toolbar by editing Commerce and setting the Shipping Surcharge option to "Yes."
Surcharges themselves are added directly to products -- edit the product you'd like to add a surcharge to in its directory and navigate to the SKU subtab. Edit or create a SKU and you will see a Surcharge field.