Discount on every 4th product

Hi-
I have a customer who would like to "motivate" his customers to buy multiples of 4 products (they can be different) as shipping is maximized at this quantity. The shop is built with Hikashop.
He would like to offer a 10% discount on the most expensive of the 4 products.
If they have 8 products, then the 2 most expensive would be discounted, and as forth.
Is this possible using AWOCoupon Pro? From what I have read, it should be. I just want to validate before purchasing.
Thanks!
Stephanie

Hello,

Yes, it is possible. You can set up a buy x get y coupon.

Value: 10%
Process type: highest value
Buy X: Number 3, asset select all the categories
Get Y: Number 1, asset select all the categories