[kmwest]

To echo what everybody said, to live in Washington or one of the closer suburbs is ridiculously expensive. Having said that, I lived in Stafford, VA (37 miles on I-95/395 to the 14th St Bridge) and paid $600/month (rent including utilities) to rent out the basement of a small townhouse. There are good public commuting options in Northern Virginia besides your car, but it'll still be a bear no matter what. If you can handle that, then you can get cheaper housing; if you want to be closer or in Washington than expect to pay a lot or be in a sketchy neighborhood.

If you do decide to live farther away in VA, I suggest looking into slugging (Slug-Lines.com - Slugging and Slug Lines Information For Washington DC). I did it when I lived in Stafford and worked in the Pentagon area and it went very well; very few complaints and it was fast most of the time.

Have fun.