Turkish Airlines has round-trip flights from Los Angeles (LAX) to Istanbul (IST) for $749, NONSTOP. Flights February to March. Departures on Monday, Tuesday, Wednesday, and Sunday.
Some small OTAs on Skyscanner have this for as low as $738; 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.