I have not switched to 3G yet... i am not even clear on how to convert my Vodafone SIM to 3G from existing 2G settings. Last month i recharged Rs 28 and got 500 MB of data valid for 30 days, you cannot get internet any cheaper than thi.s I use it on PC , images disabled, forget videos, but still , Internet at < Re.1 per day ..
although this is just a spare connection, I have a good wired connection , otherwise it is stupid to use 2G for regular browsing purpose.