Playing devil advocate to you:

actually, what the guy did was raised the floor up. Yes you lose some trunk space but doesn't mean he won't fit groceries or golf clubs. Just not big luggage.

So as for the $ and cents, Let's look at it this way. Your regular prius get 50mpg and has a 11 gallon tank giving you realistically ~500 in crusing range. At $3 a gallon for gas, that would be $33 to fill it up every 500.. Now if you can cruise 250 mpg.. your range now is ~2500 which is 5 times the efficiency. mean with 1 tank of fill up... you save $132 and time it goes to get the car filled up. (time=$) So yeah, it will take a awhile to get to $3000..

Just wait time right now for the Prius in the bay area... My brother in law has one and paid UNDER MSRP..

As for the batteries, they used bicycle batteries which are gel cells so no acid burn...

So with that said.. I'm a little jealous and I'm gonna rant... The S4 is a ridiculous gas guzzler.. The wife gets realisitcally about 12mpg on that thing.. Audi really screwed up in that regards since we get about 180 miles usually to a 16.5 gallon tank. The M5 with the upgraded Plasma coils is now getting avg of 19 mpg (which is awesome for the amount of HP this thing puts out now with the mods) I've even seen 24mpg on the freeway crusing at 80 mph... Guys with M5.. the Ignition Solutions Plasma coil = good investment.