The NEX-3 is available at jjmehtas for a price of Rs 29,500/- with a free 4GB SD card. jjmehta is one of the more reputed camera dealers so that should take care of the warranty part.
Agree that the NEX-5 does not offer significantly more than the NEX-3.
IMO, what I find the NEX-5 to offer over the NEX-3 would be
i> magnesium alloy construction vs plastic construction on tne NEX-3.
ii> better (deeper) grip than on the NEX-3.
iii> 1080i video recording as opposed to 720p recording on the NEX-3.
all of which can be given a miss given the price difference between the two.
No technical issues whatsoever with the NEX cameras. They are the cameras giving Sony all the money nowadays. Better than m43s due to the bigger sensor but the lens sizes are weird for such a small camera.