$/sqf is a poor measure of rental costs. Because a 400sf apartment in NY is not 1/2 of the cost of a 800sf apartment in NY.
EX: from the same complex. http://www.equityapartments.com/new-york/new-york-city-apart...
418 sqft from $2,920 = 6.9$/sf
727 sqft from $3,490 = 4.8$/sf