A group of 5 will be going to Hampton Inn Manhattan Grand Central. Which transport to take? If take cab what cab to take and how much?

Green cab

If you have a lot of luggage, the subway may not be the best option (although it will be the cheapest at $2.75 per person or $7.75 if you take the airtrain and then transfer to a train to Manhattan). There's also the yellow taxi option but that will cost $52 +tax, tolls, and any other surcharge -- but there's no extra charge for passengers. Lastly, there is also the Golden Touch shuttle which is advertised for $19/person from JFK to Grand Central. Those are the options I found and if you have a lot of luggage or have elderly or children, the taxi option may be most economical for a group of 5.