Look out in the Rockville/Bethesda area in Maryland too. There are lots of hotels and motels out that way, and they tend to be less pricey that the ones in downtown DC or in Crystal City. There is plenty of Metro service in that area, so you won't have any trouble getting around. See if you can download a Metro Map at www.wmata.com.
Thanks so much for the suggestion, I’ll look out there.