Depending on your lifestyle you should be able to live for considerably less in Cuba than in the U.S., Canada or Europe. Food, housing, transportation and most entertainment are cheaper and you will not have huge winter heating bills. One of the best ways to figure out if you can afford to live in Cuba is to compare your income with the wages of the workers of the country. This gives an accurate picture of your purchasing power and tells you how much you probably need to maintain your current lifestyle. The average salary in Cuba is around $20-30 dollars monthly, which says it all.
But you must not assume professionals and others earn as much as their counterparts in the U.S., Canada or Europe. A social security check of $1500-$2000 dollars a month will enable you to live far better than most professionals in the majority of Latin American countries not, to mention Cuba.
The majority of Americans and Canadians will be able to have a maid, gardener, go out to eat and drink most evenings, afford entertainment, buy clothing and food and, in general, enjoy a lifestyle as good if not better that they would at home.
Another factor making Cuba affordable is the two-tiered price system. As in most countries in Latin America, it is one thing to visit Cuba as a tourist and another to live there. Tourists stay in high-priced hotels, eat their meals in restaurants and generally live “high on the hog” by paying “top dollar" for everything. On the other hand, by residing in the country, you will save money by renting, purchasing food in markets and spending less. You will also learn to bargain or haggle for prices as done in the rest of Latin America.
However, the real secret to a low cost of living and getting more for your money is to try to "live like them locals." This does not mean you have to live in abject poverty but learn to economize in many situations.
How much money you need to live in Cuba really depends on your lifestyle. A foreigner can rent an apartment for as little as $400 to $500 dollars a month on a long-term basis. However, it will take time to find such a place, and during the time you are looking you are probably going to pay at at least $30 per night, or $900/month. So a person should budget $900-$1000 for lodging the first month, and maybe $500 (just to be on the safe side) for each month after that.
You can eat and by beverages — bottled water, juice, beer, whatever for about $10-$15 a day. This can be reduced once you learn where and how to "shop Cuban" and all of the ins and outs. This takes time to learn, so count on spending, say, $500 for food and beverage for your first month, after which you can probably manage on less.
As one person pointed out, “You may have a notion that you can save money by hanging with Cubans who will take you to the cheap places they frequent and this is true — but in exchange you will be expected to pay for them and why shouldn't you, since you are more affluent than anyone you are likely to meet.