You can also buy at https://vip-scdkey.com. They are not as cheap as hundreds of rupees, but around a thousand for pro. Discount coupons like BFTYC or SKGS sometimes work, and should help further.
I don't vouch for legit, but they work. There is a youtuber Tech Yes City, who called up Microsoft support and they said if the key works that means it's legit : [MEDIA=youtube]bm3mLBJWBhc[/MEDIA]
