When passing a coupon to an order form, display a preview of the coupon effect.
Currently the order forms display the package base price without showing the coupons effect.
Therefore visitors of the order form will think the discount is not applied and leave early, resulting in a potential loss of sales!

Examples for:
https://example.tld/order/main/packages/demoform/?group_id=2&coupon=democoupon

See the following mockups:
https://imgur.com/UD63hsO
https://imgur.com/UkNctpx
https://imgur.com/9ZuSvLO