1. See if it is possible to park at Springfield metro and taking the metro to the airport. That is cheaper than parking at DCA usually.
2. Take an Uber. Paying twice for Uber can be cheaper depending on where you live. Take an Uber XL or something if you have a lot of cargo.
3. As a last resort, park at DCA.

Lol, I used to complain a lot about the DC metro. Then I took SEPTA when I went to Philly. I told my self that I will never complain about DC metro.