Guys ,
First of all .. do ascertain if you "R E A L L Y" need live tick by tick data. Just because somebody is offering live data for 12K does not means that you need to go for it.Some of this vendors have been illegally pushing yahoo data only.
If you do really need Live tick by tick data, believe me, price is not the first criteria for selectng vendors. Check Accuracy of data, availability and price.
i know for sure that esignal, reuters and spidersoft are authorized NSE data vendor ...so before paying your money check the above parameters as well as ascertain if the vendor is a leagal authorized vendor.
Regards ,
Stumper.