$3,500 USD to start a business in Cuba, I assume you don't have the same kind of business regulations I have to deal with in Canada. I built a model of my Thrift shop business but the government rules are very frustrating.
I did practice saving a percentage of my earnings every month, not as cash but in real money like silver coins because inflation destroys too much of my buying power and my bank account only earns a mere pittance in interest after taxed.
If ever credit cards ever begin to take hold in Cuba, refuse them.
They are a financial curse.

1934 Cuba 1 Peso.
Collecting coins has been my hobby.

!LADY