Fiji Airways has round-trip flights from Dallas (DFW) to Nadi (NAN) for $701-$746, NONSTOP. Flights April to July. Departures on Tuesday, Thursday, and Saturday. Extended weekends available. Origin/Destination reversible.
Some small OTAs on Skyscanner have this for as low as $693; which is cheaper than the airline. If you plan on booking there, beware of any site that charges a fee to cancel a ticket within the 24-hour “free” period. Use unknown booking sites at your own risk.