How can I create a POS button for automatic $5 product rebate?

[michaelg3]

Hi there, I'm hoping to create a button in POS that automatically rebates a product amount by $5. The reason is that when our guests have previously purchased an experience, they receive a $5 rebate from their experience fees on a retail purchase. I don't want a discount button because it doesn't account for the reduced fees for the experience as it logs under discount and changes the way we would track. Also, applying a manually entered rebate after the product has caused a lot of human error issues and it locks you out from being able to go back and add or remove items. Does anyone know if/how this can be done? Alternatively a negatively priced product could work as well. Thanks!