Coupon logic based on compare-at price with customer control

The merchant wants the ability to create coupon codes that always calculate the discount from the regular price (compare-at price), even when a product already has a sale price. They need the system to apply the better offer automatically, so customers always receive whichever is lower: the existing sale price or the discounted coupon price. This helps them maintain clear and fair pricing while protecting their margins.

They also want customers to have control at checkout. If the sale price is better than the coupon price, the customer should be able to remove the coupon manually. In addition, the merchant would like optional messaging in the cart that clearly announces when the customer already has the best available offer, such as “You’re all set! The best price is already locked in.”

This feature would provide more transparent, flexible discount behavior and a smoother customer experience. If this would be helpful for your store as well, please upvote this request!