American Airlines has round-trip flights from Dallas (DFW) to Saint Kitts (SKB) starting at $382, NONSTOP. Flights May to August, on Saturdays only. 7-day minimum stay required. Origin/Destination is reversible.
Note: Fare allows for a free carry-on, but checked bags will cost +$30 each-way. You can avoid seat selection fees by accepting the free randomly assigned seat at the gate.