Hahaha, the prices are def high! I just window shop or watch planes take off/land.
As for whirledtraveler, I decided, on a whim, to call DCA's police station's non-emergency line and ask if I was considered to be a trespasser if I went to DCA to just watch planes, or shop, and eat, and she was very nice and said that I was welcome at DCA anytime, that it was a public place, and that I just couldn't go in the secure areas, but that I was definitely welcome.