Pricing by Manufacturing date

Dear,

I am working as a support for pharma company.They have scenario:

The pricing caluculations are changing from 1st october,but they want to keep old pricing caluculations for old stock .the system should defferentiate depending on the manufacturing date or batch wise .when they take old stock in the order the caluculation will be old pricing procedure,if the take new stock the new pricing should come.we need go live after 1st october.Is it possible in SAP can any one help on this

Regards

Chilukri