American Airlines and Southwest have round-trip flights from Dallas (DFW/DAL) to Kansas City (MCI) for $99-$118, NONSTOP. Flights June to November. No Monday departures. Extended weekends available. Origin/Destination reversible. No Thanksgiving dates.
A Carry-on bag and also a personal item is allowed for free on American. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.