It doesn't really handle luggage. I tried this the last time, and it was easy, but I only had a shoulder bag that I could put in my lap. It is a regular bus, so you might have an empty seat beside you, but no luggage storage otherwise.

The next cheapest method, with luggage facilities, is taking a Washington Flyer bus to the West Falls Church metro and continuing on the Metro.

http://www.washfly.com/

BillJ