Interesting, even with the 40% import duties (China to India), local prices still are very high. Im not sure how to explain why no one is using this arbitrage.
Usually the arbitrage is a mirage (though sometimes it's real). Many times there are hidden taxes in the form of government bribery and special red tapes that requires paying the relevant parties. You only find out this stuff when you start doing business as the details are not included in the manual.