Dear @Claudia Dineen,
without having more details about your requirement, I can just give you a generic hint on this:
Ideally every item of your backlog can deliver a business value to your companies product. To measure this you would need a direct channel of what a particular item bought in the past. I doubt that you can really measue this in € or $. But you could get a feeling for each item how much it has increased your total products business value.
Same as for estimating user stories in story points in a relative way, you can do this with the business value. The currency there should also be virtual.
Again - this is very generic - I don't know you business / market understanding or product knowledge.
We keep a simple table which lists the features to be implemented in the next release. The features are ordered by Business Value, which is 1 to n.
Features are built, according to this Business Value prioritisation.
How you determine the '1 to n' business value ordering is art, science and a bit of magic ;-)