I have done it all and my experience as well as of people I know:

we have done all the price comparison and we have found that deals,coupons etc are not worth the time. I just want a site that I can go to and be somewhat sure that I am getting a good price.

Flipkart is fantastic for that. I have never ever found a product on flipkart that is cheaper elsewhere and I can also see my other options for similar products on the same site.

If I am being adventurous, I browse ebay where I get good deals.