no way 50%...
that may be some old models for quick sale out that they must have offered 50% but not all across Dell.
And if you are buying from Dell India... I doubt you can get any discounts or any coupons
And if you are going for such a top end config I reccon you get it from US if you can. That can cost you approx 20-25k less than in India...
Again Indian warranty, service and blah blah blah things can be debated.... But I think reliability is key point when you go for branded things.
You can see the config I ordered
http://www.techenclave.com/laptop-buying-advice/please-suggest-laptop-usb-3-0-a-190394.html
The diff was almost 20k in US and India... had to wait for 2 months to wait for someone to get this for me.. but at the end its worth.....