We are a company selling software with an historic store being migrated to shopify.
As we sell software access threw licences, we have multiple types of licences and we would like to offer upgrade from one type of a licence to another at lower prices automaticly at the time of purchase.
Let say we have a product with a "standard" licence at 40€ and a "pro" licence at 60€. When a customer want to buy a pro licence the price would be 60€, unless he has already purchased the standard licence, in which case the pro licence would only cost him the 20€ difference.
Now to be more precise, we only sell pro licence nowadays, but many of our historic customers have purchased other type of licences in the past. We are currently developing a system to store old and new purchased licences in a json metafield of our customer, for them to be able to see what licences they purchased, get back their licence keys, and re-download their binaries in a dedicated page. The question being what would be the way to go to offer those reductions to our users. Are there any recommended app's that would do the job. If not, would it be technically possible for us to do so ? With the same principle we would like to offer those kind of reduction for "crossgrade" (buying a product that is replacing an old one) and bundle (to make you pay only the part of the bundle you haven't already purchased).