How are Properties Comp'ed in NYC?

[J. Lancaster]

As a new investor, I've only seen the more seasoned investors instruct on one way to Comp Non-Commercial Residential Property or anything less than a 5 Family. And that is: "Sales" of Comparable Homes within a 1/4 ( Or as much as 2 Miles further out in Rural areas ) in the last 6 months. But in NYC are properties Comp'ed strictly by calculating cost per sq. ft.? Would that still only apply to The Sale of Comparable Properties? Or would it be what a general style of house is going for in a particular area?