Usually cheap parking will be because it's after 5pm or you came early (early bird special). If a metro station has its own lot, it would be $5, but it's only for 24 hours. Since you won't be staying in a hotel, $15-25/day isn't too bad..
Today's
Living Social deal is $25 toward $50 of food at Dino, an Italian restaurant I mentioned a few posts back
Since one of you will be staying in Rosslyn, here is a food review of one of the food places there:
I was craving a salad today and wanted to go to
Chop't. As I walked by their location in Metro Center, there was a line going out the door, so I took the metro to their Rosslyn location (it's "on the way" home). I used to go to school in Rosslyn but it has been about 4 years and lots of things have changed; Chop't being one of the newer additions to International Plaza.
The thing in DC that's hot now asides from cupcakeries and $10 gourmet burgers is salad joints. Chop't is set up similar to Chipotle and designed to move the line along when it get slammed at noon. They offer chopped salads and chopped salad sandwiches. You can pick from the 13 salads they have to offer, or you can make your own. They also have about 28 different dressings. Their Chop't Spa dressings I believe are only made only with agave nectar or honey. If you like your dressing, you can even buy one to take home; they are made fresh daily. You can also get your dressing on the side.
You place your order and they toss all the ingredients in a bowl. They move it to the chopper person and he/she asks you want dressing you want. They then dump the bowl on a chopping board and mince it up, then put it in a metal bowl with the dressing, tosses it nicely, then puts it in the plastic bowl. Then you go and pay.
They have Boylan's sodas here, which are only made with cane sugar and no high fructose corn syrup. There is also Diet Coke and Boylan's has diet versions of some of their sodas as well. They also have kettle chips, brownies, blondies, cookies, and fleur de sel caramels.
I usually get the Veggie Powerhouse but today I got Steakhouse (grilled flank steak, tomato, fried onions and romaine) with blue cheese dressing. They give you a huge portion so I think for kids, one salad is enough for 2-3 servings depending on your appetite. It ended up being $10.56 for my salad and soda with tax--this is a typical price for lunch in the DC area, especially if there are a lot of office workers. I would recommend frequenting Chop't before 12 noon or after 1:30pm when crowds have died down. There is also outdoor seating available.
I love to go out and eat so if there is a place that you are curious about and isn't prohibitively expensive, post here and I will investigate!