I will be traveling to Cuba in January and booked my flight through Southwest. Like some of the other airlines mentioned previously, Southwest is partnering with Cuba Travel Services. However, they have a special offer specifically for Southwest passengers to purchase the tourist card for $50, which can then be picked at whatever airport you are flying out of (FLL or TPA, in SW case). For comparison, I live in DC and stopped by the Cuban consulate, where they also wanted $50 money order as well as some other forms and documents. Using the contracted service with CTS was much simpler as it could be done online and you can use a credit card to pay for it.