Option Trade: Buy NIFTY 6400CE Back at Rs15 or less making 4.8% in 1 week

On October 3,2010 NIFTY 6400CE was advised for a Sell at Rs50
Right now on Oct 8,2010 the same Call (NIFTY 6400CE)  is available at Rs17. It would be advisable to Buyback the Call at Rs15 (after 3.00pm IST) making Rs 35 in one week time frame.. (we should be able to buyback after 3.00pm IST at around Rs15 or lower...)

For one lot of 50 units after expenses profit would be:
Sell Price (Rs50): 50x50-Rs150(transaction cost) = 2350
Buy back Price(Rs15): 15x50+150(Transaction cost) = 900
Profit: 1450
Investment: Rs 30,000

Return: 1450/30000 = 4.8%
Waiting for One more week will give additional Rs5 reduction in buyback price.. but it is adviseable to buyback as we have achieved more than 50% of the target 7.3% return reducing our risk..