Hi Sudhir,
based on your requirement i suggest For invoicing with the new prices is accomplished by using the
1. Pricing procedure in Delivery level.
2. and for this maintain Copying controls VTFL use the Price Source " D-Delivery" and Pricing type as "B - Carry out new pricing".
by this automatically the new prices will be determined in to the billing document.
Regards,
Srinivas yadav