I never lived in DC Area but I was there last month for a visit.  I don't know what part of DC you are moving to but Arlington area (where my friend was living and DC downton is like 5  minutes walk from there ) I found it quite expensive. He is living in one bed room apartment and he said he is paying 1450 excluding any utility. The metro station,grocery stores  are ofcourse near by from his aparment. As, I never lived in DC area so can't provide much information other than this . This is just one scenario and hope that not everypart of dc area is that expensive. I hope somebody who is actually living there can provide more input

And hey congrats for you job offer. My best wishes.