Not sure I can agree. I do not know what the NiMh packs cost GM. (I would think they get them cheaper since they bought the ovonics company) But I know what lead-acid batteries cost since that is what I used in my EV and I know how many they used and their specifications. My guess is that the batteries would cost somewhere between $1,500 and $3,000 to replace. You can bet if there were tons of these cars on the road, economies of scale would bring the price down to the lower end of that guess, especially if they could be purchased aftermarket and GM didn't use some kind of proprietary battery.The battery packs in these automobiles are expensive. If they will not last the lifetime of the vehicle, the owner will be faced with a horrendous replacement cost when they fail.
If you consider that the car would generally outlast the mechanical parts of the internal combustion engine, replacing the battery pack every 5 years would still be comparible to the cost of repair on an ICE vehicle over that same time period. if you figure in the gasoline savings, the math really works.