Hi Rajkumar
The IPC is compulsory for pricing in SAP CRM whether it may be E Commerce or without it. Btw, all parts of the Internet Pricing Configurator (IPC) use now the new server infrastructure with Application Platform (AP) 2005 (e.g. delivered with CRM 5.0) and are called Pricing, Tax and Configuration Engines.
You can get clear information in here 809820 - Userexit concept for pricing. Check for attachments of the note, please.
Regards,
Aliaksei