Ya If it was me moving I would look at mabe living in the Massness and or Gainsville area of VA and commute to rt 28 which runs right beside KIAD. If you live inside the beltway you would also be paying tolls on I66 inside the beltway as well. FYI people who live in the Shenandoah Valley leave home between 3 and 3:30am to beat the traffic on I66 and or Rt 28, 15 and 211 coming up from Luray.In fact a lot of people who live in Luray commute to NoVA to work and it would not be unusual to see cars parked where side streets and rt 211 meet between Luray and Admissville.Just my .02 where to live in VA if I was working out by IAD.
The commute from Manassas to Dulles is at least an hour. It is not worth it.
Live in Dulles, Reston, Herndon or Stirling (south of Route 7). Rent four or more blocks away from the Town Center and rent drops to more reasonable rates.
There aren't tolls on I-66 (yet) just HOV.