I am going to stick to amazon from now on for all agriculture stuffs and only in rare cases will bother with other sites.
Here are the reasons:
1) Looooooooooooooong delivery times(they use Courier Land method which is even slower than Speed Post and can get so slow that you might as well order them via India Post Parcel. This delay causes the time-sensitive items like plants and compost to go bad)
2) They miss or send wrong items. And follow up is terrible.
3) Delivery charges on top of the products which they sell and sometimes even taxes are calculated separately. On amazon it's just 500 or with prime no delivery charges at all.
4) Return/Refund process is excruciatingly soul-sucking. It's like they have made a system that makes it for a normal user to go through so much hoops that they might not even bother going through it. You might say Amazon also has these problems, yes, but not this much.
That being said, amazon also has different sellers, often time the same sellers who are selling separately. Once you have gained trust with the sellers on amazon, then you can go ahead and order from them directly but I wouldn't suggest ordering from these sites before gaining their trust on Amazon first.
The first time I ordered, due to it being send through the cheaper Courier Land option it took a longer time than normal (10 days to Purnea Bihar). Also due to improper packaging I lost Amarnth Seeds. The courier guy did his best to bring the package in his big sack/bora to show what had come through and the company was willing to refund/give the product again over email but they wanted videos and other stuff which I wasn't willing to do. Will order next time and have told them about the same.