Arbitraging can be profitable but you need a big pile of money for trades in the scale of hundreds of BTC. A seriously large pile of money.
I used to think that deals like this were obviously scams... But this is not that uncommon from Asian countries, to be honest. I was recently put in touch with a buyer in South Korea who wanted me to fly in with a dozen Trezor wallets filled with 5-25BTC each on a bi-weekly basis. He asked if I could bring more, but I figured that anything more than that would tip off Customs at the airport. We had a lengthy conversation about how the regulated Bitcoin trading market is so inflated in Asia, and that he wanted to start a black market selling Bitcoin at lower prices than what they're available for in Chinese, Japanese and South Korean exchanges. He also indicated that there are hundreds, if not thousands, of individuals that do not trust the banks and have access to an insane amount of cash and gold.
I ended up feeling uncomfortable with this method of arbitrage, and the way that I was to move the fiat cash was kind of shady (Asian banks regulate and keep track of EVERYTHING, so to get caught with their fiat as a foreigner would bring a lot of question and investigation), so I turned down the offer. After that conversation, however, I don't doubt that there is a HUGE (black) market for Bitcoin in Asia.
Of course, do your own due diligence, but this could very well be a legitimate request.