Southwest Airlines has announced several daily round trips to Cuba from its Fort Lauderdale hub.
There are trips to Varadero, on the north central coast of Cuba, east of Havana, and to Havana itself.
Prices for Varadero range from as low as $59 one way on January 31, to $178 early in the month. Prices for the return trip are a little more expensive, at $90 and $209. The $31 difference seems to be consistent across the band, so that may be exit taxes, etc. February is $59 outbound and $90 for most of the flights.
Prices to Havana are a few dollars cheaper. Two flights daily to HAV, it looks like the crews lay over and return the following day. That's a little surprising, as this is just over an hour's flight. I wonder if the plane travels onward to Grand Cayman, Jamaica, etc.