Looking for a roofer in Sussex County

I'm about to close on a triplex in Newton and some issues came up during inspection, one of which was the roof needs to be replaced.  Looking for a contractor to get an estimate of what I should ask for in concession.  Closing is supposed to be this Friday (obviously getting delayed) but would like to get a general idea for what it would cost to replace a ~1750 sq foot roof.  

If anyone has any guesstimates or recommendations, please contact me.