Antivirus are of generally three kind Basic Antivirus, Internet Security and total security. Now this is a choice of user and actual requirements of user that which version he buys. Suppose if a user is not connected to internet he can buy a basic antivirus, but again if one is connected to internet and using some important websites like internet banking, credit card payments etc., he should choose total security. But the choice is entirely of customer.
Why to buy online? a very important point as every penny matters. We try to do lot of saving and invest that money some where. Now when we buy antivirus key online, it not only saves time but gives you saving from lot of middle man commissions. And that is why we are cheap. Take example of Quick heal Antivirus which is available on big brand website for X rupees can be cheaper buy Rs 100-Rs 300 and some time more then that also. Because here is no commission, no freight charges, immediate delivery.