When they first came out, the nutters who were driving insane mileage in a Prius did have to pay something like $5k for a worn out battery, but economies of scale are bringing that down for both Toyota and Honda (last I heard, a Civic's pack new could be had for about $3k), and as these things get into wrecks, I'm sure we'll start seeing rebuilt sets for even less. At roughly $500/yr gas savings (versus a 30mpg Civic, $2.50/gal), that means six years to cover a potential battery replacement, and four years to cover the original MSRP price difference (heh, the ten years minimum I want to keep it), but in all honesty, I expect the thing to start rusting out before I have to worry about the battery As far as regular maintenance goes, the thing is almost as bum standard as any other car on the road. I do oil changes myself, and can take it where-ever for stuff like alignment, gas engine tune-ups, brakes, and so on. The only thing I have to go to the stealership for is if one of the hybrid components (like a power transistor) crapped out. Since nearly everything on the road is still under warranty, there isn't any *good* (that is, not Chevy dealer BS) data out there about how much those modules cost.