There are mainly two options for that,
1)Buy a phone from a seller who sells Custom seized goods. The only problem with this is that you wont have warranty for the product you buy. But the main advantage is that there will be a huge difference in the rate of the phone as compared to the local market.
2)Buy a phone online. There are hundreds of online sites which sell electronic gadgets at get offers. These products are genuine and has company warranty for a particular period of time. This also has a great difference in the rate.