Cuba is expensive. The problem is that you can't participate in the local peso economy where everything is dirt cheap. You can only buy things with Cuban Convertibles (CCs) - the tourist currency - and the prices set for tourists make everything as expensive as if you were in the US. You will find yourself paying $3 dollars for a beer while the locals get it for around 80 cents.
For the Cubans themselves there are certain things they can only buy using the tourist currency, for example petrol and mobile phones. The advent of tourism has created a two-tier society in a country that prides itself on treating everyone equally. If you are a taxi driver, a restaurant owner, a black market trader in cigars, or even a hooker then you have access to the tourist currency and buying power beyond the dreams of ordinary Cubans - when these are converted into pesos. Thus a cigar factory worker gets the equivalent of $32 dollars a month whereas a taxi driver may get that for one fare, and a hooker can get three times that for an hour. It's no wonder that you have to fight off swarms of prostitutes whenever you go out in Havana.
Those outside the tourist circuit are being left behind. I was approached one day walking through Old Havana by a distinguished looking gentleman with long grey hair. He told me he was a history professor and asked could he give me a guided tour of the old town. I was busy and had to decline but it seemed that here was someone outside the tourist economy trying to break in.