Even with the $5,000 difference between the Prius and non-hybrid Toyotas, there was a time when Toyota lost money on the car. Even when the car entered the black, and even though they halved the cost of the hybrid system from one generation to the next, Toyota still didn't make the margins on it that they did with their go-to sedans. Yet with plans to start making batteries for the Hybrid Synergy Drive in the U.S., Toyota says it should be able to halve costs again, and bring the next-gen Prius profit to near parity with the Corolla.