On May 6, 2020, Tony Cooper wrote
(in ):



On arriving, we had to purchase $100 in Cuban currency. We could not
exchange any Cuban currency back to US currency, and anything we had
left had to be spent in the airport shop or taken back home.

Except for ice cream sold in a square in Havana, there was little of
interest to spend money on while were there, so most of us had most of
the $100 left. One peso was US $1.00 at the government exchange, but
Cubans would offer up to 5 pesos for an American dollar. It was
illegal to do that, though, and I never did.

Today there are two rates for the Cuban Peso, Normal, or Cuban Convertible Peso:

Normal Cuban Peso: CUP1= US $0.039 / $1= CUP25.75

Cuban Convertible Peso: CUC$1= US $1

So for you not too much has changed since 1979. I guess US tourists get special treatment.

--
Regards,
Savageduck