What is an HB I...or Prius I These seem to be cheaper and indicate late availability. What is the difference compared to others - like the Prius II? Is this a striped version for the rental market?
Yes, it's a stripped down model for fleets, which often includes the rental market. That said, I know someone who recently rented a Prius IV with sunroof in FLA, so some will still get the better equipped models. All depends on the level of demand.
I am betting that the prius I is more for non rent-a-car fleets. more for like, company employees who have to drive. Rent a car places usually get medium trimmed vehicles.