Discounts To Only Selected Products

I do pre-sales for certain events that offer a discount on packages I offer if purchased in advance. Is there a way to apply a coupon or a credit to a customer but ONLY for a specific package? As an example, if a package costs $175 after the event, but I offer a pre-order sale of $155 - Currently I see I can only issue a credit or a coupon for $175 so they can get their package, but there is no way to stop them from say ordering different products that might add up to that $175 instead of the package they originally ordered.

There is not a way to  only discount certain products.

But what you can do is create a new price list for your pre-orders and you can override the price of the products in the price list. See attached.

You can also take an existing price list and duplicate it instead of creating one from scratch.