Promo code applied UI

I'm currently working on the UX/UI for a flight app. The promo has to be applied before searching as only certain flights are on promotion. Once the Promo is applied I am having trouble displaying to the user how much they have saved because of space constraints. It's currently a block W:319 H:48 currently filled with flight info leaving W:68 H:48 to indicate the price difference. I've been researching other flight apps, many of them scratch out the first price and highlight the second in a positive color. Is there any other way of doing this?