Want to buy a diamond engagement ring

Hello ladies!

I am coming to New Delhi and Bangalore in 2nd half of March, and want to buy a diamond engagement ring for my fiance'. I wonder if I can get better prices there than in California?

If so, I can spend about $3,000 US and cannot go too far from my hotel.

How should I prepare to buy, and where do you recommend I go?

I think that women are the best to ask in this case! 8^)

Thank you!