CareScout's Cost of Care Survey is designed and published at the state level only, across every state it covers -- there is no metro-specific breakout for New York City, Staten Island, or any other individual region within the state, from CareScout or from any other primary source we could locate.
The detail behind the number
This is a structural limitation of the survey itself, not something specific to New York or to Staten Island being under-covered. The same limitation applies to every metro area in every state CareScout surveys, which is why the honest, defensible approach is to cite the state median explicitly as a state median, note that local pricing likely differs, and stop there rather than inventing a number to fill the gap.
Some websites present a "local" cost figure that is, on closer inspection, just the state median relabeled with a city name, or a number pulled from a small, unrepresentative sample of listings. Treat any Staten Island-specific cost claim you encounter elsewhere with real skepticism unless the source clearly explains where the number actually came from.