Awesome guys!!! More options than I expected. As Valentine mentioned, it is the time to start looking into the tradeoff. As of now, I don't have the requirements such as volume/frequency of requests.
On the otherhand - to minimize the development time, I'm looking forward to get the shopping cart frame work and customizing it to my needs. Pointers to any open source available in the web are welcome.
Thank you all for your replies.
Regards,
Soggadu