Core Charges

Client uses parts that have core charges.  These charges are similar to deposits that are paid by consumers on soda bottles.  They are charged when the items are initially purchased, and then credited back when the item is sent back to the supplier for recycling, re-use, etc. 

My client is using basic distribution systems, which does not include functionality for tracking these charges.  They are similar to inventory, but the items cannot be counted, since they are part of other items.  In addition, sometimes the core charges have other characteristics, such as expiration dates. 

I'm curious to see if any other manufacturing or distribution consultants have any solutions for handling core charges.  This may include handling them within the Inventory system, or handling them in any other system.