We just got back from our cruise and rented a car in Santorini and Corfu. In Santorini we paid 40 euros for a minivan that fit 7 people and in Corfu we paid 90 euros for a 9 passenger minivan (our friends paid 60 at a different location). Other friends paid 25 euros for a 4 passenger car. They were all stick shift.
It was great, we were able to drive around to see the island at our pace.