Say there were 2 cars which one do you buy ! Just throwing this out there................. 2008 -100,000 miles $9,000 2005-40,000 miles $9,000 just say both cars were in excellent shape what's really the better deal !
Before either mileage or age I would be checking history for signs of damage. It sure seems a lot of Prius are 'repaired' by folks who know more about body panels and paint than about hybrid systems. CARFAX® - Official Site - Vehicle History Reports on Used Cars for Sale Service History Online - Toyota Owners