Are you using yahoo feed through Market Data Provider or any other way?
Anyway Yahoo feed is good but I have red about some glitches and errors in their data on traderji or somewhere else. Moreover it might be delayed, there chart on website is.
Any way don't go for it , especially if you are putting real money on trading as there is not much price differnces b/w yahoo feed and MDP feed. The yahoo feed offered by Manshi RT or even MDP do cost around Rs.350 I suppose. MDP's own feed is Rs.600. So go for it.
MDP feed is RT , I tried mathcing it with quotes on PIB and found no difference in quotes. They were updating realtime and even candle form of current min changed with new data.
Any way , download MDP , and they will give you free 3 days worth or trial before asking for money. Download it , read the manuals , and set Amibroker to retrieve data from it, and take the trial , try matching the quotes with your online brokerage firms software and anything else that you may want to test.
One more thing , don't download tomorrow , do that on Monday so that you may try it for 3 working market days and not one day and 2 holidays.
Rs. 600 data feed is good enough to learn initially while trading one stock at a time.