I don't know much about grey market. I was comparing the price of first party Nintendo games that are sold online.
The Legend of Zelda: Breath of the Wild (released 2 years 6 months ago) and Super Mario Odyssey (released 1 year 11 months ago) are still sold at ₹4500+ on various online stores (amazon.in, gameloot.com, gamestheshop.com). So I don't think a 5 days old Zelda game is going to be found online for anything less than that price.
In addition to that, I checked the price of Link's Awakening on Amazon US, and Amazon DE. The prices are listed as $59( ~₹4187) and €54.99(~₹4299) respectively. Considering the shipping cost involved, getting Link's Awakening in India, 4 days after launch at ₹4500 is as best as it could get.