Earlier last week, American began accepting reservations for their new regularly scheduled flights between Miami (MIA) and five Cuban airports. The flights are scheduled to begin in September and the discounts being offered provide fares under $300 roundtrip. The cheaper tickets do have a minimum stay requirement of three nights (including a Sunday night) and travel must be booked by this upcoming Tuesday for travel between September 7th – November 15th. American’s flight to Cienfuegos is pricing as low as $285, while flights to Santa Clara, Matanzas, and Camagüey can be found for $286.
You cannot yet redeem AAdvantage miles (or Avios) for American Airlines flights to Cuba, though that’s currently in the works for a late 2016, early 2017 launch. Update -It seems that points can now be redeemed for Cuba flights, though the process can be a bit daunting according to The Points Guy. See the link within the comments section for details.