How to use "Buy X Get Y - Fixed Price: Buy X get Y for $9.99" action

To enable the ‘Fixed Price: Buy X get Y for $9.99’ action of the Special Promotions extension, follow the instructions below.
The ‘fixed price’ action implies that the ‘Y’ product is discounted to a fixed price and sold when the predefined ‘X’ ones are purchased. In this case, if a customer purchases 3 cameras, he/she can buy any camera tripod for just $100.

How to configure the ‘Fixed Price: Buy X get Y for $9.99’ action?

• Go to the Admin Panel>Promotions>Shopping Cart Price Rules (click ‘Add New Rule’ button) >Actions;
• Select ‘Percent Discount: Buy X get Y Free’ for the ‘Apply’ field;
• Configure the ‘Number of Y Products’ setting to identify the number of ‘Y’ items that will receive a discount;
• Apply ‘Number of X Products’ setting to define the number of ‘X’ items. If you set 1 here, it means a customer will have to buy at least 1 ‘X’ items to get the ‘Y’ one for a fixed price;
• Go to the conditions section of the ‘Actions’ tab to point out ‘X’ items, by which the discount is triggered. As an example, we indicated that ‘X’ items should be from category with ID 18 (Eyeglasses);
• Indicate to which categories the discounted items (Y items) will belong in the ‘Promo Categories’ field;
• Besides, you can define SKUs of the individual products to which the discount should be applied (these are Y items as well). If you choose both categories and SKUs here, the discount will be applied for both items and products from the categories.

Make sure ‘X’ items differ from ‘Y’ items.

And here's the result for the rule above