Yes, car rental is expensive compare with USA, generally the rental start at 60 cuc ~ 70 usd per day with this car (Hyundai ato 2009) 

![enter image description here][1]


  [1]: https://i.sstatic.net/xCp78.jpg

plus the insure that is around 300 usd, returnable at the end of the contract if you don't have any issue.

There are others alternatives, like rent a car to a natural person, in this link you can see the cuban version of craiglist

http://www.revolico.com/autos/alquiler/