For example, if you add the cost of a 240V home charger, professionally installed, it could add thousands to the cost. On the other hand, it may be partly offset with tax credits.
Sales tax on the difference can be significant, 7% of $8,500 is $600, or 9 months of cost advantage gone.
12c/kWh electricity may be a rosy assumption for some, such as Californians. What if you had to pay 15c/kWh, or in Hawaii, 27c/kWh?
On the plus side, the alternative to the Volt might not be a 30mpg vehicle, it could be a 25mpg vehicle. But then again, it could cost $20,000 instead of $25,000, adding another $5,000 to the payoff barrier!
I have also read stories on forums that some Chevrolet dealers are planning on charging thousands over MSRP. This won't last long, they are just going to make extra money on the early adopters, and will have to make deals when demand collapses at those prices.
I think I need to make a spreadsheet.