For online shopping you should keep the following tips in mind:
(1)Read the listing details precisely before putting your orders. It is very important because you will get the product of item requested just according to the listing details.
(2) Buy online from reputed portals like Amazon, Flipkart, Paytm, Snapdeal etc.
(3) Check the feedback/reputation of the seller if you are buying from a marketplace website. It is better to buy from a seller with a good reputation.
(4) To ensure you are getting the best price, double check with other sources. If the company is a valid manufacturer of the product, then you can be sure the prices are the best. Most e-commerce companies tend to be re-sellers/traders/middlemen hence they add their commissions on the end price - The price you pay.
(5) Remember Cash on Delivery is the best method of payment only if you inspect/test product before paying.
(6) Double check the shipping prices. Many companies inflate their shipping prices above the standard logistics providers fees, to make profits.