Re: just got a job offer...
Yeah housing sucks in nova, but w/ 70k, i think you will be fine (not living in the ghetto eating instant noodles everyday). I think if you're in NOVA and make under 50k, try to find a roomate, under 40k get 2, 30k get 3, etc...
I know alot of people who live in Prince William County, even STAFFORD, and make the commute to DC. Housing is cheaper down there, but rising. Depends on how much you like driving. Also, look into Metro options, see what stations are around.
Good luck. Welcome to northern VA. I hope you like cops and traffic.