Is anyone aware of anything available that integrates with IC and OE that extends or replaces the contract pricing?  Typically the following:

• Multiple contract prices for the same customer/item to allow different start/end dates.  This allows contracts to be set up in advance with new ones coming into effect on the set dates.
• Allow for volume agreements so a contract quantity is stored.  Quantities delivered reduce the outstanding contract balance.

This is a fairly standard thing in volume stock industries like packaged food but I have never found anything to do it.