How to add these Price values as valid Facet sources?

I'm trying to construct a Facet for Prices that are tied to Price List values (that are set according to an "active store" that the end-user chooses, and are each tied to a Product Variation).

Products have multiple variations that affect their base price values. But there are dozens of "stores" that serve up unique Price Lists that have unique price values per variation per product.

We need a single Facet, ideally, that allows the end-user to filter according to Pricing that reflects the prices set by the store that the user has selected (that serves up unique Price Lists for all Products on our search page).

When adding a new Facet, the Price List values are not available as data sources. What is the best course of action to resolve this?

I was considering maybe an 'aggregate field' that accepts a specific value ("the lowest price across all variations per store"), and using this as our Facet data source, but I am not sure if this is the best approach, and it seems really unnecessarily complex.