Southwest has round-trip flights from San Antonio (SAT) to Washington, D.C. (DCA) for $106-$130, with a connection. $53-$67 each-way. Flights sparse and scattered from March to May. Mostly Monday, Tuesday, Wednesday, and Saturday. Origin/Destination reversible.
Note: Southwest doesn’t charge bag fees, change fees, or cancellation fees. If you’ve already purchased a Southwest ticket, and the fare drops, you can call them to have the difference refunded to you in the form of a travel voucher.
Note: You can save an additional $100 if you purchase your Flight+Hotel together as a package on Southwest Vacations and use the ANYUSA coupon-code.