Well, you top shelf people may spend $30 on a bottle of liquor....
We were on Empress of the Seas Nov 4-10 - were in Havana November 6-7 (stayed overnight on ship). (and yes, what the heck ever happened to my trip report writing)
Empress let us bring bottles of rum obtained in Havana back on board to our cabins. (Maybe they did not want to have to store the many hundreds of bottles of rum that may have been bought.)
The Captain became the new beloved hero of most of the passengers for this decision.
You could get a good bottle of rum for about $8 in Havana - or other liquor.
I wonder how much the sales of alcoholic drinks dropped after being in Havana - I know of a good number of lost sales from personal observation. But, who knows, maybe there was no significant drop in sales overall.
BTW: we had a great cruise on Empress - small ship but great crew. We very much enjoyed seeing Havana. I knew that we would see old American cars, but I was amazed at how many there are and how great they looked. All of the Cubans we met were very friendly and welcoming - and all seemed to have at least one relative living in the USA - if not a big branch of their family tree.
As we participated in the hundreds of cruise ship passengers swarming ashore and spending lots of money - including with tips and gifts - and the way that the Cuban people seemed so welcoming - the idea that the overall embargo continues really seemed kind of silly.