Worst case it will cost you about $2,376 for the school year ($6222*9=$2,376 for 5 days/week; 9 months per year) and ~ $1,404/$1,836 if you schedule your classes for 3/4 days per week (MWF/M-T). Do they have monthly discounts for the express bus from SI? As @MYOS1634 suggested, there might be some alternatives, but it will not be as cost effective as commuting. Some NYU students rent large apartments in Brooklyn (roommates) and commute to NYU.
Years ago, I took the bus and train to CCNY and the commute was close to 1h15m - 1h30m, 5 days per week. Read my textbooks on the train and the commute was never an issue for us back then.