American Airlines and Fiji Airways have round-trip flights from Austin (AUS) to Nadi (NAN) for $754-$781 with a connection. Flights January to October. Departures on Tuesday, Thursday, and Saturday. Extended weekends available.
Some small OTAs on Skyscanner have this for as low as $688; 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.
Priceline is priced as low as $729 and they allow for free cancellation if you cancel within 24-hours after booking.
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.