Sign Nexus 5 Customs (Dubai to India)

I'm planning to buy nexus 5 from Dubai, I want to know how much customs department will charge me if I bring it with me to India? Can I bring it along with the Phone sealed BOX? or opening it is better.

BTW: Is this the right time to buy Nexus 5 since Silver is about to release?
Samsung Galaxy N2 / N3