Fiji Airways have round-trip flights from Los Angeles (LAX) to Nadi (NAN) for $677, NONSTOP. Flights August to May. Extended weekends available.
Some small OTAs on Skyscanner and Google have this for as low as $626; 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.
Hopper is advertising a -$100 off coupon for Fiji Airways, but it doesn’t seem to work. We weren’t able to pull up any working dates with Hopper’s coupon.