Thanks much for the feedback! My main concern with the 2006 Prius is the age of the battery, and the miles due to other concerns like compression, power on hills, oil leaks and consumption. Your comments have helped me to reconsider.
I thought once the battery pack went out that the car wouldn't drive at all and would have to be towed, but according to
this video at 1:07, the car can still be driven at slower speeds. Is that correct? Also,
this video shows how to test, balance and change the bad cells.
As long as these things are correct, the 2006 Prius is my #1 choice.