Wow, after reading these comments and a little research, I realize that the city/highway difference on the Prius isn’t as great as I believed. I thought it was the reverse of a gas or diesel powered car, but that is clearly not the case. Considering the current price difference between diesel and gasoline, the Prius makes more sense from a strictly economic sense.
Having driven both the Prius and the TDI I know I’d rather drive the TDI, but that’s a personal choice.