Power Information Network said the average price of a Prius with 8,000 miles in June was $27,945, which is $1,300 more than the price of a new one, USA Today reported Friday.
A 2007 Prius has depreciated slightly. With an average of 22,000 miles, a 2007 Prius sold for $276 below the price of a new one, the newspaper reported.
"Demand for fuel-efficient vehicles is so strong that the customer is willing to buy used ones at a significant premium," Tom Libby of the Power Information Network said.
Toyota said recently it would begin Prius production in 2010 at a new plant in Blue Springs, Miss., to help meet the sudden demand.
"There is just a frenzy on the car," Don Mushin, general manager of Toyota of Hollywood, told USA Today. "At the end of the month, I won't have a Prius on the ground."