I'm sitting in a DCA crashpad in Crystal City right now. There are 4 US Air/MidAtlantic ones that I know of including this one.
If your going to be based in DCA I would suggest being in a crashpad in Arlington, DC or Alexandria. I can be at the airport in 20 minutes which means that I can be out doing what I want, get a call and have planty of time to mosey back to the pad, shower, get ready and show up. From Crystal City to the airport you can walk, take the metro or go to U HQ and get the shuttle that goes every 30 minutes. Since our pad is 2 blocks from HQ I usually take the company shuttle.
This area is very $$$. All rich people and govt money. You can eat off the sidewalks. Plenty to do. Bike paths all over if you bring a bike but everything is within walking or a short metro ride. If I had the $$ I'd get my own place and move here but once again this area is $$$. The only apartments around here that I found that I could possibly swing myself if I moved here are 40 min south down by Quantico/Dale City. The crashpads that I know of range from 160 to 300+.
As for hotels if you need to go that way try the Americana in Arlington. 50 or 80 dollar crew rate depending on the time of year.
PM me and I'll get you the numbers for the ones that I know of.