How to apply business logic to paginated search data?

Question

Background: We have an eCommerce site that uses Oracle Endeca to search and filter for products and return the search results paginated. Unfortunately, we have custom backend logic that applies special pricing depending on the customer, which only gets applied to the Endeca paginated results. Our backend system is archaic (if you must know, Progress WDS-II). Also unfortunate, is that we allow the user to sort the results by (Catalog) Price. So, the problem is that the calculated price shown is actually sorted.

Question: Does anyone have any suggestions on how to handle this scenario? Architecturally, are there good designs for how you should apply business logic and calculate fields post-query? Or is it as simple as "Don't do it"? How do other search engines like elasticsearch or Lucene apply business logic to the search results?