Are you sure you want to live in MD and commute to National Airport? Have you seen the traffic on that commute nowadays? I can understand not wanting to live in VA (me too), but you need to understand what you're getting yourself into.
Look at
GreatSchools.net as a way to compare schools within the county.
I think in Chevy Chase, a smallish townhouse within walking distance of the Metro will run you in the $500's. It seems like most of the town houses in the area don't have yards for some reason. Maybe a little farther from the Metro you can find something for less that's still in the same school district. There are also lots of condos around Bethesda/Chevy Chase.
I've also heard people talk about living in NW DC and paying a fee to send their kids to public school in Montgomery County. I don't know anything about that, but a friend of mine got a single family house in a nice part of NW for what a townhouse typically goes for in Chevy Chase, so that might be worth looking into.