Here's a nice little joint in downtown DC.
http://www.theswissinn.com/ $79-160/night
http://washingtondc.craigslist.org/doc/vac/280603650.html $100/night sleeps 4-5 - I think this one is perfect
http://washingtondc.craigslist.org/doc/vac/278137283.html This one is expensive $300
http://www.wantedweb.com/dcvacations.html I havent looked through here
http://www.theswissinn.com/ $79-160/night
http://washingtondc.craigslist.org/doc/vac/280603650.html $100/night sleeps 4-5 - I think this one is perfect
http://washingtondc.craigslist.org/doc/vac/278137283.html This one is expensive $300
http://www.wantedweb.com/dcvacations.html I havent looked through here