Will I buy that dress or not is not the concern here. The concern is shipping charges & GST. I think you have not understood what I said in my first response in this thread. I will give you an example. Suppose a trouser is listed at Amazon and there are two sellers for the trousers. One seller is selling the same trouser for Rs 1000 inclusive of shipping and GST. The other seller is selling the same trouser for, say, Rs 950 plus Rs 50 as shipping charges. The cost of the trouser is same for you in both the cases, i.e. Rs 1000. Both are paying the same amount of GST.
Shipping charges depend on the following factors - weight, dimensions, distance. There are different slabs for weight - 500gm, 1000gm, 1500gm.......for dimensions, it is L*B*H/5000. If L*B*H/5000 is less than 2500, then it falls in 0-500gm slab, if it is between 2500-5000, then it falls in 500-1000gm slab. Courier companies charge for whichever is higher between dead weight and volumetric weight. For distance, there are zones like local, zonal, and national. Some e-commerce portals charge you flat for shipping, some charge by the zones.
Mohan, you are once again mistaken about Amazon. Amazon, Snapdeal and Flipkart have their own courier services. The rest of the e-commerce portals have tied up with private courier services to deliver their orders. the courier services do not charge heavily to these e-commerce portals, since they give them something around 50,000 packets everyday from Metros like New Delhi, Mumbai, Kolkatta, Chennnai, Bengaluru, Ahemdabad...
Hope it clears your doubts!
When you talk, you are only repeating what you already know. But if you listen, you may learn something new!