There's some kind of federal tax break on all hybrid vehicles at the moment. I believe it was $2000 at one point and it might be down to $1000 right now. Before the tax break the difference from the EX to the Hybrid is $2390. Overall it's not such a huge jump.

As for the Prius, its base price is higher than the Civic Hybrid and can be loaded up with a bunch of options to push the sticker over $26k. Even with that pricing structure Toyota is selling more of em than they can build. I'd say that while there are the folks that buy a Prius for its eco-pod-ness, there are also enough people crossing over from the mainstream to make it commercially viable.