I've been told that you have to have travel medical insurance to enter Cuba, although it sounds like enforcement isn't universal (some people aren't asked about it, maybe younger people? Others are forced to buy Cuban insurance in the airport). How much is the Cuban insurance, or what is the cheapest option for this for a long term stay, 90 days or more?
PC Financial offers this for under $270 for 90 days, but that is still very expensive IMO as I've never had to buy travel insurance for any of the malarial swamps I've lived in, e.g. Solomon Islands, Thailand, Brazil, etc. For poor travellers this is onerous.